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1.
Kensuke Shiraishi Kousaku Mimura Shinichiro Izawa Ayako Inoue Shugo Shiba Takanori Maruyama Mitsuaki Watanabe Yoshihiko Kawaguchi Masayuki Inoue Hideki Fujii Koji Kono 《Gastric cancer》2013,16(4):571-580
Background
Trastuzumab has been recently approved for clinical use to treat HER2-expressing advanced gastric cancer, and anti-HER2-targeting therapy has become a promising option for gastric cancer. Lapatinib is a dual tyrosine kinase inhibitor targeting EGFR and HER2. The aim of the present study was to explore the utility of lapatinib for gastric cancer, with a particular focus on trastuzumab-mediated antibody-dependent cellular cytotoxicity (ADCC).Methods
Nine gastric cancer cell lines were evaluated for the effects of lapatinib on the cell-surface accumulation of HER2 and analyzed for their additional effects on trastuzumab-mediated ADCC. Also, HER2 signaling with Western blot, proliferative function with the MTT assay, and apoptosis-inducing activity with 7ADD/Annexin-V were investigated when a panel of gastric cancer cell lines was treated with lapatinib.Results
Lapatinib inhibited HER2 signaling and cell proliferation in the panel of gastric cancer cell lines. Lapatinib also induced the accumulation of HER2 on the cell surface, resulting in the enhancement of trastuzumab-mediated ADCC of gastric cancer.Conclusions
Lapatinib exhibits inhibitory activity in gastric cancer cells, and the combination of lapatinib with trastuzumab may be a promising treatment strategy for gastric cancer patients. 相似文献2.
Wang YC Morrison G Gillihan R Guo J Ward RM Fu X Botero MF Healy NA Hilsenbeck SG Phillips GL Chamness GC Rimawi MF Osborne CK Schiff R 《Breast cancer research : BCR》2011,13(6):R121-19
Introduction
The human epidermal growth factor receptor 2 (HER2)-targeted therapies trastuzumab (T) and lapatinib (L) show high efficacy in patients with HER2-positive breast cancer, but resistance is prevalent. Here we investigate resistance mechanisms to each drug alone, or to their combination using a large panel of HER2-positive cell lines made resistant to these drugs.Methods
Response to L + T treatment was characterized in a panel of 13 HER2-positive cell lines to identify lines that were de novo resistant. Acquired resistant lines were then established by long-term exposure to increasing drug concentrations. Levels and activity of HER2 and estrogen receptor (ER) pathways were determined by qRT-PCR, immunohistochemistry, and immunoblotting assays. Cell growth, proliferation, and apoptosis in parental cells and resistant derivatives were assessed in response to inhibition of HER or ER pathways, either pharmacologically (L, T, L + T, or fulvestrant) or by using siRNAs. Efficacy of combined endocrine and anti-HER2 therapies was studied in vivo using UACC-812 xenografts.Results
ER or its downstream products increased in four out of the five ER+/HER2+ lines, and was evident in one of the two intrinsically resistant lines. In UACC-812 and BT474 parental and resistant derivatives, HER2 inhibition by T reactivated HER network activity to promote resistance. T-resistant lines remained sensitive to HER2 inhibition by either L or HER2 siRNA. With more complete HER2 blockade, resistance to L-containing regimens required the activation of a redundant survival pathway, ER, which was up-regulated and promoted survival via various Bcl2 family members. These L- and L + T-resistant lines were responsive to fulvestrant and to ER siRNA. However, after prolonged treatment with L, but not L + T, BT474 cells switched from depending on ER as a survival pathway, to relying again on the HER network (increased HER2, HER3, and receptor ligands) to overcome L's effects. The combination of endocrine and L + T HER2-targeted therapies achieved complete tumor regression and prevented development of resistance in UACC-812 xenografts.Conclusions
Combined L + T treatment provides a more complete and stable inhibition of the HER network. With sustained HER2 inhibition, ER functions as a key escape/survival pathway in ER-positive/HER2-positive cells. Complete blockade of the HER network, together with ER inhibition, may provide optimal therapy in selected patients. 相似文献3.
Toshiro Shimo Junichi Kurebayashi Naoki Kanomata Tetsumasa Yamashita Yuji Kozuka Takuya Moriya Hiroshi Sonoo 《Breast cancer (Tokyo, Japan)》2014,21(1):75-85
Background
Although the poly adenosine diphosphate (ADP)-ribose polymerase (PARP) inhibitor olaparib is known to have potent antitumor activity in BRCA-related breast cancer cells, a limited number of preclinical and clinical studies have shown antitumor activity of olaparib in non-BRCA-related breast cancer. We investigated antitumor activity of olaparib in breast cancer cell lines derived from patients with nonfamilial sporadic breast cancer.Methods
Effects of olaparib alone or in combination with five different chemotherapeutic agents on cell growth, cell cycle progression, apoptosis, and proportion of cancer stem cells using the mammosphere assay and CD44/CD24/ESA cell surface marker assay were investigated in a panel of six sporadic breast cancer cell lines. Extracellular-signal-regulated kinase (ERK) phosphorylation was also investigated to elucidate action mechanisms of olaparib.Results
Olaparib inhibited the growth of two estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer cell lines and two ER-negative and HER2-negative breast cancer cell lines (50 % growth inhibitory concentrations 1.3–3.0 μM) associated with G2/M accumulation and induction of apoptosis. In contrast, two HER2-positive cell lines were resistant to olaparib. Interestingly, olaparib significantly decreased the proportion of putative cancer stem cells in either sensitive or resistant cell lines. In addition, olaparib increased expression of p-ERK. Combined treatments of olaparib with a mitogen-activated protein kinase kinase (MEK) inhibitor U0126 completely suppressed expression of p-ERK. These treatments also inhibited the G2/M accumulation and apoptosis induction by olaparib. Among five chemotherapeutic agents commonly used for breast cancer treatment, only an irinotecan metabolite SN38 showed additive antitumor activity with olaparib. Importantly, the combined treatment enhanced the increase in G2/M accumulation and apoptosis induction as well as a decrease in the proportion of cancer stem cells.Conclusions
This study has indicated for the first time that the PARP inhibitor olaparib has substantial antitumor and anticancer stem cell activity in breast cancer cell lines of nonfamilial origin. Upregulation of p-ERK might explain, at least in part, antitumor and anticancer stem cell activity of olaparib. Combined treatment of olaparib with irinotecan might be effective in treatment of non-BRCA-related breast cancer. 相似文献4.
Background
A novel antibody–drug conjugate (trastuzumab-DM1, T-DM1) is currently in clinical trials for patients with trastuzumab resistant HER2-positive breast cancer. Since no clinical data is available from gastric cancer, we studied T-DM1 on HER2-positive human gastric cancer cells and xenograft tumors.Methods
Effects of T-DM1 were studied in four HER2-positive gastric cancer cell lines (N-87, OE-19, SNU-216 and MKN-7) in vitro. Xenograft tumors from N-87 and OE-19 were studied to determine the effect of T-DM1 in vivo.Results
T-DM1 was found more effective than trastuzumab in N-87 and OE-19, and moderately effective in MKN-7 cells. On SNU-216 cells both trastuzumab and T-DM1 showed limited efficacy. In xenograft tumor experiments, complete pathological response was observed in all OE-19 xenografted mice and in half of the N-87 xenografted mice. The results were equally good irrespective of the tumor burden at therapy initiation, or preceding trastuzumab treatment. T-DM1 treatment showed direct effects (apoptotic cell death and aberrant mitosis) as well as it mediated antibody-dependent cellular cytotoxcity (ADCC).Conclusions
T-DM1 showed a promising anti-tumor effect in HER2-positive gastric cancer cell lines in vitro and in vivo, even in tumors which had developed resistance to trastuzumab. T-DM1 therapy may warrant clinical trials for HER2-positive gastric cancer patients. 相似文献5.
Hideko Akagi Hajime Higuchi Hidetoshi Sumimoto Toru Igarashi Ayano Kabashima Hiroyuki Mizuguchi Motoko Izumiya Gen Sakai Masayuki Adachi Shinsuke Funakoshi Shoko Nakamura Yasuo Hamamoto Takanori Kanai Hiromasa Takaishi Yutaka Kawakami Toshifumi Hibi 《Gastric cancer》2013,16(1):100-110
Background
Myeloid cell leukemia-1 (Mcl-1) is an anti-apoptotic protein that regulates apoptosis sensitivity in a variety of cell types. Here we evaluate the roles of Mcl-1 in chemotherapy-associated apoptosis in gastric cancer cells. In addition, our study examined whether Mcl-1 contributed to apoptosis resistance in so-called cancer stem cell (CSC)-like populations in gastric cancer.Methods
Seven gastric cancer cell lines were used. The expression of Mcl-1 was assessed by either real-time polymerase chain reaction or Western blot analysis. Apoptosis was quantitated by morphological observation and caspase activity measurement. Adenovirus-mediated RNA interference (RNAi) technology was used to knockdown the expression of Mcl-1. The release of cytochrome c was evaluated by subcellular fractionation and immunoblot analysis. To identify and isolate the CSC-like populations, we used the CSC-associated cell surface marker CD44 and flow cytometry.Results
Six out of the 7 gastric cancer cell lines overexpressed Mcl-1 protein. These Mcl-1-expressing cell lines were relatively resistant to chemotherapeutic agents such as 5-fluorouracil (5-FU) and cisplatin (CDDP). Depletion of Mcl-1 protein by RNAi technology effectively sensitized the cells to anticancer drug-induced mitochondrial cytochrome c release, caspase activation, and apoptosis. In addition, vast amounts of Mcl-1 mRNA were expressed in CD44-positive CSC-like cells. Mcl-1 suppression enhanced the apoptosis in CD44-positive cells to a level equivalent to that in CD44-negative cells, suggesting that Mcl-1 mediates chemotherapy resistance in CSC-like populations.Conclusion
These results suggest that Mcl-1 mediates the resistance to apoptosis in gastric cancer cells by blocking the mitochondrial pathway of cell death. Mcl-1 depletion appears to be an attractive strategy to overcome chemotherapy resistance in gastric cancer cells. 相似文献6.
Yoshiki Kataoka Hiroshi Okabe Akihiko Yoshizawa Sachiko Minamiguchi Kenichi Yoshimura Hironori Haga Yoshiharu Sakai 《Gastric cancer》2013,16(1):84-93
Background
A recent randomized controlled trial (Trastuzumab for Gastric Cancer [ToGA] study) established standard scoring criteria of human epidermal growth factor receptor 2 (HER2) for gastric cancer and demonstrated the efficacy of trastuzumab for treating metastatic gastric cancer. The aim of the present study was to evaluate the frequency of HER2-positive cases by application of the standard criteria in patients with resectable gastric cancer and to examine the relationships between HER2 expression and prognosis, mucin phenotype, p53 status, and clinicopathological features.Methods
A total of 213 patients were included in this retrospective study. All tumor samples were examined for HER2 expression by immunohistochemistry (IHC), HER2 amplification by in situ hybridization, and mucin and p53 expression by staining for CD10, MUC2, MUC5AC, MUC6, and p53.Results
HER2-positive tumors were identified in 25 patients (11.7 %). HER2-positive cases were more frequently found in men, older patients, and in the intestinal histological type (P = 0.0048, 0.0309, and <0.0001, respectively). Although no association was found between HER2 overexpression and mucin phenotype, the expression of CD10 and p53 was significantly correlated with HER2 positivity (P = 0.0079 and 0.013). The overall survival of HER2-negative and -positive patients was not significantly different. However, in patients with stage III/IV, overall survival was worse in HER2-positive patients (P = 0.0149). In a comparison between dual-color in situ hybridization (DISH) and fluorescence in situ hybridization (FISH), four IHC2+/3+ cases that were DISH-positive were judged as negative by FISH.Conclusions
Our study indicated that HER2 expression was less frequent in resectable gastric cancer than in metastatic gastric cancer. The impact of HER2 expression on survival was limited. DISH was superior to FISH for evaluating cases with limited HER2 expression. 相似文献7.
Yashiro M Qiu H Hasegawa T Zhang X Matsuzaki T Hirakawa K 《British journal of cancer》2011,105(10):1522-1532
Background:
Acquired drug resistance to irinotecan is one of the significant obstacles in the treatment of advanced gastric cancer. This study was performed to clarify the effect of epidermal growth factor receptor (EGFR) inhibitors in combination with SN38, an active metabolite of irinotecan, on the proliferation of irinotecan-refractory gastric cancer.Methods:
Two irinotecan-resistant gastric cancer cell lines, OCUM-2M/SN38 and OCUM-8/SN38 were, respectively, established by stepwise exposure to SN38 from the parent gastric cancer cell lines OCUM-2M and OCUM-8. The combination effects of two EGFR inhibitors, gefitinib and lapatinib, with SN38 on proliferation, apoptosis, and cell cycle on gastric cancer cells were examined.Results:
Gefitinib or lapatinib showed synergistic anti-tumour effects against OCUM-2M/SN38 and OCUM-8/SN38 cells when used in combination with SN38, but not against OCUM-2M or OCUM-8 cells. SN38 increased the expression of EGFR and HER2 in OCUM-2M/SN38 and OCUM-8/SN38 cells. The combination of an EGFR inhibitor and SN38 significantly increased the levels of apoptosis-related molecules, caspase-6, p53, and DAPK-2, and resulted in the induction of apoptosis of irinotecan-resistant cells. The EGFR inhibitors increased the S-phase and decreased the UGT1A1 and ABCG expression in irinotecan-resistant cells. The SN38 plus Lapatinib group more effectively suppressed in vivo tumour growth by OCUM-2M/SN38 cells than either alone group.Conclusion:
The combination treatment with an EGFR inhibitor and irinotecan might produce synergistic anti-tumour effects for irinotecan-refractory gastric cancer cells. The regulation of SN38 metabolism-related genes and cell cycle by EGFR inhibitors might be responsible for the synergism. 相似文献8.
Jin Q Yuan LX Boulbes D Baek JM Wang YN Gomez-Cabello D Hawke DH Yeung SC Lee MH Hortobagyi GN Hung MC Esteva FJ 《Breast cancer research : BCR》2010,12(6):R96-15
Introduction
The human epidermal growth factor receptor 2 (HER2) is a validated therapeutic target in breast cancer. Heterodimerization of HER2 with other HER family members results in enhanced tyrosine phosphorylation and activation of signal transduction pathways. HER2 overexpression increases the translation of fatty acid synthase (FASN), and FASN overexpression markedly increases HER2 signaling, which results in enhanced cell growth. However, the molecular mechanism and regulation of HER2 and FASN interaction are not well defined. Lapatinib is a small-molecule tyrosine kinase inhibitor that blocks phosphorylation of the epidermal growth factor receptor and HER2 in breast cancer cells, resulting in apoptosis. We hypothesized that FASN is directly phosphorylated by HER2, resulting in enhanced signaling and tumor progression in breast cancer cells.Methods
Using mass spectrometry, we identified FASN as one of the proteins that is dephosphorylated by lapatinib in SKBR3 breast cancer cells. Immunofluorescence, immunoprecipitation, Western blotting, a kinase assay, a FASN enzymatic activity assay, an invasion assay, a cell viability assay and zymography were used to determine the role of FASN phosphorylation in invasion of SKBR3 and BT474 cells. The FASN inhibitor C75 and small interfering RNA were used to downregulate FASN expression and/or activity.Results
Our data demonstrated that FASN is phosphorylated when it is in complex with HER2. FASN phosphorylation was induced by heregulin in HER2-overexpressing SKBR3 and BT474 breast cancer cells. Heregulin-induced FASN phosphorylation resulted in increased FASN enzymatic activity, which was inhibited by lapatinib. The FASN inhibitor C75 suppressed FASN activity by directly inhibiting HER2 and FASN phosphorylation. Blocking FASN phosphorylation and activity by lapatinib or C75 suppressed the activity of matrix metallopeptidase 9 and inhibited invasion of SKBR3 and BT474 cells.Conclusions
FASN phosphorylation by HER2 plays an important role in breast cancer progression and may be a novel therapeutic target in HER2-overexpressing breast cancer cells. 相似文献9.
Hannah Schmucker Walker M. Blanding Julia M. Mook Jessica F. Wade Jang Pyo Park Kerri Kwist Hiral Shah Brian W. Booth 《Cellular oncology (Dordrecht)》2018,41(2):159-168
Purpose
Tumor initiation and progression rely on cellular proliferation and migration. Many factors are involved in these processes, including growth factors. Amphiregulin (AREG) is involved in normal mammary development and the development of estrogen receptor (ER)-positive breast cancer. The aim of this project was to determine if AREG is involved in the proliferation and progression of HER2-positive breast cancer.Methods
Mouse cell lines MMTV-neu, HC-11 and COMMA-D, as well as human cell lines MCF10A, SKBR3, HCC1954 and BT474 were used. Real-time PCR was used to quantify AREG expression and neutralizing antibodies were used to reduce the autocrine/paracrine effects of AREG. Transfections using siRNA and shRNA were used to knockdown AREG expression in the cancer cell lines. Free-floating sphere formation, colony forming, scratch wound and Transwell assays were used to assess the proliferation, tumor forming and migratory capacities of transfected cancer cells.Results
We found AREG expression in both normal epithelial cell lines and tumor-derived cell lines. Knockdown of AREG protein expression resulted in reduced sphere sizes and reduced sphere numbers in both mouse and human cancer cells that overexpress erbB2/HER2. AREG was found to be involved in cancer cell migration and invasion. In addition, we found that AREG expression knockdown resulted in different migration capacities in normal and erbB2/HER2 overexpressing cancer cells.Conclusions
Based on our results we conclude that AREG is involved in regulating the proliferation and migration of erbB2/HER2-positive breast cancer cells.10.
Astrid O. Leech Sri HariKrishna Vellanki Emily J. Rutherford Aoife Keogh Hanne Jahns Lance Hudson Norma O’Donovan Siham Sabri Bassam Abdulkarim Katherine M. Sheehan Elaine W. Kay Leonie S. Young Arnold D. K. Hill Yvonne E. Smith Ann M. Hopkins 《Breast cancer research : BCR》2018,20(1):140
Background
Junctional adhesion molecule-A (JAM-A) is an adhesion molecule whose overexpression on breast tumor tissue has been associated with aggressive cancer phenotypes, including human epidermal growth factor receptor-2 (HER2)-positive disease. Since JAM-A has been described to regulate HER2 expression in breast cancer cells, we hypothesized that JAM-dependent stabilization of HER2 could participate in resistance to HER2-targeted therapies.Methods
Using breast cancer cell line models resistant to anti-HER2 drugs, we investigated JAM-A expression and the effect of JAM-A silencing on biochemical/functional parameters. We also tested whether altered JAM-A expression/processing underpinned differences between drug-sensitive and -resistant cells and acted as a biomarker of patients who developed resistance to HER2-targeted therapies.Results
Silencing JAM-A enhanced the anti-proliferative effects of anti-HER2 treatments in trastuzumab- and lapatinib-resistant breast cancer cells and further reduced HER2 protein expression and Akt phosphorylation in drug-treated cells. Increased epidermal growth factor receptor expression observed in drug-resistant models was normalized upon JAM-A silencing. JAM-A was highly expressed in all of a small cohort of HER2-positive patients whose disease recurred following anti-HER2 therapy. High JAM-A expression also correlated with metastatic disease at the time of diagnosis in another patient cohort resistant to trastuzumab therapy. Importantly, cleavage of JAM-A was increased in drug-resistant cell lines in conjunction with increased expression of ADAM-10 and -17 metalloproteases. Pharmacological inhibition or genetic silencing studies suggested a particular role for ADAM-10 in reducing JAM-A cleavage and partially re-sensitizing drug-resistant cells to the anti-proliferative effects of HER2-targeted drugs. Functionally, recombinant cleaved JAM-A enhanced breast cancer cell invasion in vitro and both invasion and proliferation in a semi-in vivo model. Finally, cleaved JAM-A was detectable in the serum of a small cohort of HER2-positive patients and correlated significantly with resistance to HER2-targeted therapy.Conclusions
Collectively, our data suggest a novel model whereby increased expression and cleavage of JAM-A drive tumorigenic behavior and act as a biomarker and potential therapeutic target for resistance to HER2-targeted therapies.11.
Yokoyama H Ikehara Y Kodera Y Ikehara S Yatabe Y Mochizuki Y Koike M Fujiwara M Nakao A Tatematsu M Nakanishi H 《British journal of cancer》2006,95(11):1504-1513
Gastric cancer metastasised to the liver was found to overexpress HER2 at a significantly higher incidence than primary gastric cancers. The purpose of the present study was to investigate the possibility of molecular therapy targeting HER2 overexpression in gastric cancer liver metastasis. We developed three new HER2-overexpressing gastric cancer cell lines (GLM-1, GLM-2, GLM-4) without epidermal growth factor receptor (EGFR) mutations derived from such liver metastasis, two of which had HER2 gene amplifications. All these GLM series of cell lines were highly sensitive to gefitinib in vitro, a specific inhibitor of EGFR tyrosine kinase (Iressa) rather than anti-HER2 antibody trastuzumab (Herceptin), whereas most of the HER2 low-expressing counterparts were not. In these HER2-overexpressing GLM series, protein kinase B (Akt), but not extracellular signal-regulated kinase 1/2 (ERK1/2), was constitutively phosphorylated, and gefitinib efficiently inhibited this Akt phosphorylation, induced strong apoptosis in vitro and exhibited antitumour activity in tumour xenografts in nude mice. This gefitinib-mediated antitumour effect in xenograft was significantly potentiated by trastuzumab treatment. On the other hand, gefitinib-resistant cells (GLM-1R) exhibited increased EGFR expression, followed by constitutive activation of mitogen-activated protein kinase (MAPK) pathway. These results suggest that the antitumour effect of gefitinib is due to the effective inhibition of HER2-driven constitutive activation of phosphatidylinositol-3-kinase (PI3K)/Akt pathway, and that the acquired resistance to gefitinib is due to the constitutive activation of Ras/MAPK pathway in compensation for PI3K/Akt pathway. Gastric cancer liver metastasis with HER2 overexpression would be a potential molecular target for gefitinib and trastuzumab. 相似文献
12.
M Toi H Iwata Y Fujiwara Y Ito S Nakamura Y Tokuda T Taguchi Y Rai K Aogi T Arai J Watanabe T Wakamatsu K Katsura C E Ellis R C Gagnon K E Allen Y Sasaki S Takashima 《British journal of cancer》2009,101(10):1676-1682
Background:
HER2-positive metastatic breast cancer (MBC) relapsing after trastuzumab-based therapy may require continued HER2 receptor inhibition to control the disease and preserve the patients'' quality-of-life. Efficacy and safety of lapatinib monotherapy was evaluated in Japanese breast cancer patients after trastuzumab-based therapies.Methods:
In studies, EGF100642 and EGF104911 evaluated the efficacy and safety of oral lapatinib given 1500 mg once daily in patients with advanced or MBC. All patients progressed on anthracyclines and taxanes; HER2-positive patients had also progressed on trastuzumab.Results:
For HER2-positive tumours (n=100), objective response rate was 19.0% (95% confidence interval (CI): 11.8–28.1) and clinical benefit rate (CBR) was 25.0% (95% CI: 16.9–34.7). One out of 22 HER2-negative tumour was documented as complete response (n=22). The median time-to-progression (TTP) in the HER2-positive and HER2-negative groups was 13.0 and 8.0 weeks (P=0.007); median overall survival was 58.3 and 40.0 weeks, respectively. The most frequent adverse event was diarrhoea. TTP and CBR were significantly associated with HER2 expression. Patients with tumours harbouring an H1047R PIK3CA mutation or low expression of PTEN derived clinical benefit from lapatinib.Conclusion:
Lapatinib monotherapy had shown anti-tumour activity in Japanese patients with HER2-positive MBC that relapsed after trastuzumab-based therapy, including those with brain metastases. Patients benefiting from lapatinib may have biomarker profiles differing from that reported for trastuzumab. 相似文献13.
Background
Lapatinib is a commonly used drug that interrupts signaling from the epidermal growth factor receptors, EGFR and HER2/neu. Long-term exposure to lapatinib during therapy eliminates cells that are sensitive to the drug; however, at the same time it increases probability of lapatinib-resistant cell selection. The aim of this study was to verify whether combinations of lapatinib with one of isothiocyanates (sulforaphane, erucin or sulforaphene), targeting different levels of HER2 signaling pathway, exert stronger cytotoxic effect than therapy targeting the receptor only, using heterogeneous populations consisting of lapatinib-sensitive and lapatinib-resistant breast cancer cells.Methods
Lapatinib-sensitive HER2 overproducing SKBR-3 breast cancer cells and their lapatinib-resistant derivatives were combined at different proportions to simulate enrichment of cancer cell population in a drug-resistant fraction during lapatinib therapy. Effects of treatments on cell survival (MTT), apoptosis induction (PARP cleavage), prosurvival signaling (p-Akt, p-S6) as well as cell motility (wound healing assay) and invasion (Boyden chamber assay) were investigated.Results
Combination of lapatinib with any of isothiocyanates significantly decreased cell viability and inhibited migration of populations consisting of different amounts of drug-sensitive and drug-resistant cells. In case of population entirely composed of lapatinib-resistant cells the most effective was combination of lapatinib with erucin which decreased cell viability and motility, phosphorylation of Akt, S6 and VEGF level more efficiently than each agent alone.Conclusions
Combination of lapatinib and isothiocyanates, especially erucin, might be considered as an effective treatment reducing metastatic potential of breast cancer cells, even these with the drug resistance phenotype.14.
Wenle Xia Emanual F Petricoin III Sumin Zhao Leihua Liu Takuya Osada Qing Cheng Julia D Wulfkuhle William R Gwin Xiaoyi Yang Rosa I Gallagher Sarah Bacus H Kim Lyerly Neil L Spector 《Breast cancer research : BCR》2013,15(5):R85
Introduction
The human epidermal growth factor receptor 2 (HER2) receptor tyrosine kinase (RTK) oncogene is an attractive therapeutic target for the treatment of HER2-addicted tumors. Although lapatinib, an FDA-approved small-molecule HER2 and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), represents a significant therapeutic advancement in the treatment of HER2+ breast cancers, responses to lapatinib have not been durable. Consequently, elucidation of mechanisms of acquired therapeutic resistance to HER-directed therapies is of critical importance.Methods
Using a functional protein-pathway activation mapping strategy, along with targeted genomic knockdowns applied to a series of isogenic-matched pairs of lapatinib-sensitive and resistant cell lines, we now report an unexpected mechanism of acquired resistance to lapatinib and similar TKIs.Results
The signaling analysis revealed that whereas HER2 was appropriately inhibited in lapatinib-resistant cells, EGFR tyrosine phosphorylation was incompletely inhibited. Using a targeted molecular knockdown approach to interrogate the causal molecular underpinnings of EGFR-persistent activation, we found that lapatinib-resistant cells were no longer oncogene addicted to HER2-HER3-PI3K signaling, as seen in the parental lapatinib-sensitive cell lines, but instead were dependent on a heregulin (HRG)-driven HER3-EGFR-PI3K-PDK1 signaling axis. Two FDA-approved EGFR TKIs could not overcome HRG-HER3-mediated activation of EGFR, or reverse lapatinib resistance. The ability to overcome EGFR-mediated acquired therapeutic resistance to lapatinib was demonstrated through molecular knockdown of EGFR and treatment with the irreversible pan-HER TKI neratinib, which blocked HRG-dependent phosphorylation of HER3 and EGFR, resulting in apoptosis of resistant cells. In addition, whereas HRG reversed lapatinib-mediated antitumor effects in parental HER2+ breast cancer cells, neratinib was comparatively resistant to the effects of HRG in parental cells. Finally, we showed that HRG expression is an independent negative predictor of clinical outcome in HER2+ breast cancers, providing potential clinical relevance to our findings.Conclusions
Molecular analysis of acquired therapeutic resistance to lapatinib identified a new resistance mechanism based on incomplete and "leaky" inhibition of EGFR by lapatinib. The selective pressure applied by incomplete inhibition of the EGFR drug target resulted in selection of ligand-driven feedback that sustained EGFR activation in the face of constant exposure to the drug. Inadequate target inhibition driven by a ligand-mediated autocrine feedback loop may represent a broader mechanism of therapeutic resistance to HER TKIs and suggests adopting a different strategy for selecting more effective TKIs to advance into the clinic. 相似文献15.
Y J Liu D Shen X Yin P Gavine T Zhang X Su P Zhan Y Xu J Lv J Qian C Liu Y Sun Z Qian J Zhang Y Gu X Ni 《British journal of cancer》2014,110(5):1169-1178
Background:
Gastric cancer (GC) is a leading cause of cancer deaths worldwide. Since the approval of trastuzumab, targeted therapies are emerging as promising treatment options for the disease. This study aimed to explore the molecular segmentation of several known therapeutics targets, human epidermal growth factor receptor 2 (HER2), MET and fibroblast growth factor receptor 2 (FGFR2), within GC using clinically approved or investigational kits and scoring criteria. Knowledge of how these markers are segmented in the same cohort of GC patients could improve future clinical trial designs.Methods:
Using immunohistochemistry (IHC) and FISH methods, overexpression and amplification of HER2, FGFR2 and MET were profiled in a cohort of Chinese GC samples. The correlations between anti-tumour sensitivity and the molecular segments of HER2, MET and FGFR2 alterations were further tested in a panel of GC cell lines and the patient-derived GC xenograft (PDGCX) model using the targeted inhibitors.Results:
Of 172 GC patients, positivity for HER2, MET and FGFR2 alternations was found in 23 (13.4%), 21 (12.2%) and 9 (5.2%) patients, respectively. Positivity for MET was found in 3 of 23 HER2-positive GC patients. Co-positivity for FGFR2 and MET was found in 1 GC patient, and amplification of the two genes was found in different tumour cells. Our study in a panel of GC cell lines showed that in most cell lines, amplification or high expression of a particular molecular marker was mutually exclusive and in vitro sensitivity to the targeted agents lapatinib, PD173074 and crizotinib was only observed in cell lines with the corresponding high expression of the drugs'' target protein. SGC031, an MET-positive PDGCX mouse model, responded to crizotinib but not to lapatinib or PD173074.Conclusions:
Human epidermal growth factor receptor 2, MET and FGFR2 oncogenic driver alterations (gene amplification and overexpression) occur in three largely distinct molecular segments in GC. A significant proportion of HER2-negative patients may potentially benefit from MET- or FGFR2-targeted therapies. 相似文献16.
Yoko Chihara Masafumi Shimoda Ami Hori Ako Ohara Yasuto Naoi Jun-ichiro Ikeda Naofumi Kagara Tomonori Tanei Atsushi Shimomura Kenzo Shimazu Seung Jin Kim Shinzaburo Noguchi 《Breast cancer research and treatment》2017,166(1):55-68
Purpose
Resistance against anti-HER2 drugs in HER2-positive breast cancer is a major obstacle to the improving prognosis. Transforming growth factor β (TGFβ) is a cytokine involved in the acquisition of more malignant phenotypes through epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties. The aim of this study was to investigate the effects of TGFβ and its downstream SMAD pathway on resistance to anti-HER2 drugs.Methods
HER2-positive breast cancer cell lines were stimulated with TGFβ for 14 days. Then, the sensitivity to trastuzumab and lapatinib and the expression levels of various EMT and CSC markers were examined. The correlation of nuclear SMAD3 expression in untreated breast tumor tissues with trastuzumab efficacy in neoadjuvant settings was examined. The effect of a small-molecule inhibitor of SMAD3 (SIS3) on resistance to anti-HER2 drugs was explored.Results
We found that continuous activation of the TGFβ-SMAD3 pathway induced resistance to anti-HER2 drugs and CSC traits in HER2-positive breast cancer cells. The induction of drug resistance by TGFβ required strong activation of SMAD3. In fact, activated SMAD3 regulated multiple genes that harbor SMAD-binding elements and are involved in trastuzumab resistance. Nuclear SMAD3 expression in tumor tissue was inversely correlated with sensitivity to neoadjuvant treatment with trastuzumab. SIS3 not only prevented the acquisition of resistance to anti-HER2 drugs but also restored trastuzumab sensitivity in trastuzumab-resistant cells.Conclusions
This study indicates that the TGFβ-SMAD3 pathway plays an important role in the induction and maintenance of resistance to anti-HER2 drugs. Thus, SMAD3 is a potential therapeutic target that can inhibit resistance and restore sensitivity to anti-HER2 drugs.17.
Bartsch R Berghoff A Pluschnig U Bago-Horvath Z Dubsky P Rottenfusser A DeVries C Rudas M Fitzal F Dieckmann K Mader RM Gnant M Zielinski CC Steger GG 《British journal of cancer》2012,106(1):25-31
Background:
Trastuzumab-based therapy after diagnosis of brain metastases (BM) may improve survival due to prolonged systemic disease control. We investigated whether lapatinib may yield additional survival benefit.Methods:
Eighty patients with BM from HER2-positive breast cancer were identified. Karnofsky Performance Score (KPS) of at least 70 was required. We included a control group of 37 patients treated before 2003, when continuation of trastuzumab after diagnosis of BM was not yet recommended. Remainders received either trastuzumab or lapatinib and trastuzumab (either concomitantly or sequentially) with or without chemotherapy.Results:
Median overall survival (OS) in patients receiving trastuzumab after diagnosis of BM was 13 months; corresponding numbers were 9 months in patients treated with chemotherapy, and 3 months with radiotherapy alone. Median OS was not reached in the lapatinib group. Addition of lapatinib prolonged OS over trastuzumab alone (P=0.002). After correction for potential confounders, lapatinib therapy remained an independent positive predictor for survival (HR 0.279; P=0.012).Interpretation:
This retrospective single-centre study suggests that the introduction of lapatinib improved survival in patients with BM from HER2-positive breast cancer. Patients with KPS ⩾70 may benefit when treated with lapatinib in addition to trastuzumab after completion of local therapy. 相似文献18.
Luigi Formisano Lucia Nappi Roberta Rosa Roberta Marciano Claudia D’Amato Valentina D’Amato Vincenzo Damiano Lucia Raimondo Francesca Iommelli Antonella Scorziello Giancarlo Troncone Bianca Maria Veneziani Sarah J Parsons Sabino De Placido Roberto Bianco 《Breast cancer research : BCR》2014,16(3):R45
Introduction
Src tyrosine kinase overactivation has been correlated with a poor response to human epidermal growth factor receptor 2 (HER2) inhibitors in breast cancer. To identify the mechanism by which Src overexpression sustains this resistance, we tested a panel of breast cancer cell lines either sensitive or resistant to lapatinib.Methods
To determine the role of Src in lapatinib resistance, we evaluated the effects of Src inhibition/silencing in vitro on survival, migration, and invasion of lapatinib-resistant cells. In vivo experiments were performed in JIMT-1 lapatinib-resistant cells orthotopically implanted in nude mice. We used artificial metastasis assays to evaluate the effect of Src inhibition on the invasiveness of lapatinib-resistant cells. Src-dependent signal transduction was investigated with Western blot and ELISA analyses.Results
Src activation was higher in lapatinib-resistant than in lapatinib-sensitive cells. The selective small-molecule Src inhibitor saracatinib combined with lapatinib synergistically inhibited the proliferation, migration, and invasion of lapatinib-resistant cells. Saracatinib combined with lapatinib significantly prolonged survival of JIMT-1-xenografted mice compared with saracatinib alone, and impaired the formation of lung metastases. Unexpectedly, in lapatinib-resistant cells, Src preferentially interacted with epidermal growth factor receptor (EGFR) rather than with HER2. Moreover, EGFR targeting and lapatinib synergistically inhibited survival, migration, and invasion of resistant cells, thereby counteracting Src-mediated resistance. These findings demonstrate that Src activation in lapatinib-resistant cells depends on EGFR-dependent rather than on HER2-dependent signaling.Conclusions
Complete pharmacologic EGFR/HER2 inhibition is required to reverse Src-dependent resistance to lapatinib in breast cancer. 相似文献19.
Hiroji Iwata Masaru Narabayashi Yoshinori Ito Shigehira Saji Yasuhiro Fujiwara Shigeyuki Usami Koichi Katsura Yasutsuna Sasaki 《International journal of clinical oncology / Japan Society of Clinical Oncology》2013,18(4):621-628
Background
It is known that one third of patients with human epidermal growth factor receptor 2 (HER2)-overexpressing metastatic breast cancer (MBC) treated with trastuzumab will develop brain metastases. As the development of brain metastases is fatal, controlling its progression is clinically meaningful. However, effective therapy for MBC patients with brain metastasis after cranial radiation is limited. The international clinical study in which six Japanese patients participated indicated the antitumor activity of lapatinib against brain metastases of HER2-overexpressing breast cancer.Methods
The efficacy, safety, and pharmacokinetics of lapatinib 750 mg given twice daily to Japanese HER2-overexpressing MBC patients with brain metastases were assessed as part of the international clinical study.Results
Of six Japanese patients treated in this study, two patients had shown volumetric reduction >20 % in their central nervous system (CNS), one of whom had >50 % reduction. Three patients, including two of these patients, had shown >20 % volumetric reduction in non-CNS lesions. Frequently reported adverse events were diarrhea and rash, all of which were controllable. The AUC0–12 of lapatinib on day 28 was 1.74 times higher than that on day 1.Conclusion
These results suggest that lapatinib monotherapy 750 mg given twice daily can exert some efficacy and has potential as a clinically meaningful treatment option for Japanese HER2-overexpressing breast cancer patients with brain metastases after cranial radiation. 相似文献20.
Cristina Grávalos Carlos Gómez-Martín Fernando Rivera Inmaculada Alés Bernardo Queralt Antonia Márquez Ulpiano Jiménez Vicente Alonso Rocío García-Carbonero Javier Sastre Ramon Colomer Hernán Cortés-Funes Antonio Jimeno 《Clinical & translational oncology》2011,13(3):179-184