Prolactin overexpression by MDA-MB-435 human breast cancer cells accelerates tumor growth

Prolactin (PRL) is an important hormone in mammary tumorigenesis in rodents but its involvement in human breast cancer has been controversial. A role for locally produced PRL in breast carcinogenesis is suggested by its mitogenic action on breast cancer cells and the expression of both PRL and its receptor (PRL-R) in breast carcinomas. Our objective was to examine whether PRL, overexpressed by breast cancer cells, forms an autocrine/paracrine loop that confers a growth advantage for tumors. MDA-MB-435 breast cancer cells overexpressing 23K human PRL were generated, and PRL production and secretion by the clones were confirmed by RT-PCR, western blotting, and the Nb2 bioassay; control clones contain vector only. In vitro the 23K PRL clones proliferated faster and expressed higher levels of the PRL-R protein than controls only when incubated in charcoal-stripped serum (CSS) devoid of lactogenic hormones. When injected into the mammary fatpad of female nude mice or subcutaneously into males, the PRL-overexpressing clones formed tumors that grew 2–4-fold faster than tumors derived from control clones or wild type MDA-MB-435 cells. Western analysis demonstrated significantly higher PRL, PRL-R, and bcl-2 levels in the tumors overexpressing PRL compared to control tumors. These data support a role for breast PRL as a growth/anti-apoptotic factor and suggest that it may serve as a novel therapeutic target for the treatment of breast cancer.     

Estrogen dependent expression of the receptor tyrosine kinase axl in normal and malignant human breast

Background:Axl, a member of a family of receptor tyrosinekinases characterized by an extracellular domain resembling celladhesion molecules and an intracellular conserved tyrosine kinase domainhas been reported to induce cell proliferation and transformation. Inmice, axl is expressed in the normal mammary gland and over-expressed inaggressive mammary tumors. Patients and methods:We have investigated the expression ofaxl immunohistochemically in 23 normal human breast samples and in 111consecutive breast carcinomas. Expression of axl was correlated withtumour characteristics (lymph node involvement, stage, grade) andimmunohistochemical expression of ER, PR, Ki-67 and c-erbB-2. Results:In normal tissue, axl localizes to the membrane ofbreast epithelial cells. Axl protein shows membrane associated stainingin high correlation (P = 0.004) with the expression of theestrogen receptor (ER). Axl expression was found in a subset of breastcarcinomas and was also correlated with high significance(P < 0.0001) with the presence of ER. Conclusion:Our results suggest that axl may serve as amediator of estrogen stimulation preventing the completion of the breastepithelial life cycle and that estrogen induced axl expression may givea survival signal to cancerous cells, preventing them from dying throughapoptosis.     

FADD phosphorylation is critical for cell cycle regulation in breast cancer cells

Anti-oestrogen therapy is effective for control of hormone receptor-positive breast cancers, although the detailed molecular mechanisms, including signal transduction, remain unclear. We demonstrated here that long-term tamoxifen treatment causes G2/M cell cycle arrest through c-jun N-terminal kinase (JNK) activation, which is dependent on phosphorylation of Fas-associated death domain-containing protein (FADD) at 194 serine in an oestrogen (ER) receptor-positive breast cancer cell line, MCF-7. Expression of a dominant negative mutant form of MKK7, a kinase upstream of JNK, or mutant FADD (S194A) in MCF-7 cells suppressed the cytotoxicity of long-term tamoxifen treatment. Of great interest, similar signallings could be evoked by paclitaxel, even in an ER-negative cell line, MDA-MB-231. In addition, immunohistochemical analysis using human breast cancer specimens showed a close correlation between phosphorylated JNK and FADD expression, both being significantly reduced in cases with metastatic potential. We conclude that JNK-mediated phosphorylation of FADD plays an important role in the negative regulation of cell growth and metastasis, independent of the ER status of a breast cancer, so that JNK/FADD signals might be promising targets for cancer therapy.     

BCSC-1基因异位表达对人小细胞肺癌细胞增殖的抑制效应

背景与目的:人乳腺癌候选抑制蛋白1(breast cancer suppressor candidate 1,BCSC-1)基因已被证实是一种新型抑癌基因,在多种肿瘤细胞均存在表达缺失的现象。该研究通过将BCSC-1基因转染至人小细胞肺癌细胞株NCI-H446,探讨BCSC-1基因异位表达对NCI-H446细胞增殖的抑制效应。方法:用PCR扩增BCSC-1 cDNA,构建真核重组表达载体pcDNA3.1/v5-HisB-BCSC-1。通过脂质体把pcDNA3.1/v5-HisB-BCSC-1和空质粒pcDNA3.1/v5-HisB转染入野生型NCI-H446细胞。以转染空质粒pcDNA3.1/v5-HisB的NCI-H446细胞为对照组,野生型NCI-H446细胞为空白对照组。采用流式细胞仪检测细胞周期;MTT法检测细胞增殖;免疫组化确认BCSC-1基因和CD44分子在NCI-H446细胞中的表达。结果:成功构建了真核重组表达载体pcDNA3.1/v5-HisB-BCSC-1,制备了BCSC-1基因异位高表达的NCI-H446稳定细胞株。细胞周期分析显示,异位表达BCSC-1的NCI-H446细胞大部分阻滞在G0/G1期,明显高于对照组和空白组(P<0.01)。MTT法检测显示,异位表达BCSC-1的NCI-H446细胞与对照组、空白组相比,生长速度明显减慢(P<0.05)。免疫组化显示异位表达BCSC-1的NCI-H446细胞CD44表达增高。结论:BCSC-1基因的异位表达对NCI-H446细胞的恶性增殖行为有明显的抑制作用,这种抑制作用可能与细胞周期阻滞和黏附分子CD44表达增高有关。     

Cell growth inhibition by all-trans retinoic acid in SKBR-3 breast cancer cells: involvement of protein kinase Calpha and extracellular signal-regulated kinase mitogen-activated protein kinase

All-trans retinoic acid (ATRA), a synthetic derivative of vitamin A, inhibits the growth of breast cancer cells. To elucidate the mechanism by which ATRA causes cell growth inhibition, we examined changes in cell cycle and intracellular signaling pathways, focusing on protein kinase C (PKC) and mitogen-activated protein kinase (MAPK). Using the estrogen receptor-negative, retinoid receptor-positive breast cancer cell line SKRB-3, we found that treatment with ATRA significantly decreased the expression of PKCalpha, as well as reducing ERK MAPK phosphorylation. ATRA treatment leads to dephosphorylation of Rb, and consequently to G(1) arrest. Marked changes in the expression of cyclins (particularly cyclins A and E) were observed in SKBR-3 cells treated with ATRA. Using a series of pharmacological and molecular approaches, we found evidence that ATRA-induced SKBR-3 cell growth inhibition involves the deregulation of the PKCalpha-MAPK pathway. These data suggest that retinoids interfered with signal transduction pathways that are crucial for cell cycle progression, and highlight the complexities of the biological effects of retinoid derivatives.     

Characterisation of integrin-linked kinase signalling in sporadic human colon cancer

The putative oncogene, integrin-linked kinase (ILK) is a protein serine/threonine kinase that has been reported to regulate a number of biological properties including anchorage-independent cell cycle progression, tumour cell invasion and apoptosis. Overexpression of ILK has been documented in a wide variety of human malignancies including Ewing's sarcoma (ES), primitive neural ectodermal tumours (PNETs) and prostate tumours (PT). We recently reported that ILK signalling was also dysregulated in patients with the genetic condition familial adenomatous polyposis (FAP), a precursor to colon cancer. In this study, we extended our previous work by investigating the ILK-signalling pathway in sporadic human colon cancer and representative lymph node metastases. The data indicate that the ILK protein is significantly hyperexpressed in malignant acini in relation to normal crypts. Moreover, overexpression of ILK not only coincided with increased MBP phosphotransferase activity but as well with effects on downstream targets like GSK3beta. Based upon the presented data, we propose that ILK signalling is dysregulated early during the development of human colon cancer, and that selective inhibition of this molecule alone or in combination with the standard therapeutic modality might be a more effective means of treating colon cancer.     

多西紫杉醇对乳腺癌细胞增殖及侵袭力影响的研究

目的探索多西紫杉醇对人类乳腺非肿瘤细胞和乳腺癌细胞增殖及侵袭力的影响。方法应用MTT法检测多西紫杉醇对人乳腺细胞HBL100、人乳腺腺癌细胞MCF7和人乳腺导管癌细胞MDA MB435增殖的影响,采用Tran swell法明确该3株细胞的侵袭能力及多西紫杉醇对其侵袭能力的影响。结果在人乳腺细胞HBL100、人乳腺腺癌细胞MCF7和人乳腺导管癌细胞MDA MB435中,MDA MB435S侵袭力最高(425.20±54.09),MCF7次之(239.00±91.39),HBL100侵袭力最低(101.00±63.88)。1.0PPC(药物血浆峰浓度)的多西紫杉醇处理24h后,MDA MB435S和MCF7细胞的侵袭力分别为18.20±4.32和58.40±50.53,显著低于未处理的对照组(P值分别为0.000和0.013)。不同浓度的多西紫杉醇(0.1、1.0和10.0PPC)分别与3株细胞共同孵育24、48、72和96h,其对3株的增殖的抑制率均随着作用时间的延长以及给药浓度的增大而升高。结论多西紫杉醇对3株细胞的增殖抑制作用呈时间及浓度依赖性;并明显抑制MCF7和MDA MB435S细胞的侵袭能力。多西紫杉醇是一个通过抑制肿瘤细胞生长和侵袭双重途径起效的、具有很好的靶向性的抗肿瘤新药。     

Combined effect of vitamin D3 analogs and paclitaxel on the growth of MCF-7 breast cancer cells in vivo

Vitamin D3 analogs and paclitaxel (Taxol) are able to inhibit the in vitro growth of a variety of malignant cells including breast cancer cells. These two compounds decrease growth by different mechanisms and they have non-overlapping toxicities. We examined the abilities of three vitamin D3 compounds to inhibit growth of a human mammary cancer (MCF-7) in BNX triple immunodeficient mice either alone or with Taxol. Vitamin D3 analogs were 1,25(OH)2D3 (code name, Compound C), 1,25(OH)2-16-ene-23-yne-19-n or-26,27-F6-D3 (Compound LH), and 24a,26a,27a,-trihomo-22,24-diene-1,25(OH)2D3 (EB1089). At the doses chosen, the antitumor effect of vitamin D3 analogs alone was greater than that of Taxol alone, and an additive effect was observed when a vitamin D3 analog and Taxol were administered together. EB1089 was the most potent compound, and the EB1089 plus Taxol was the most active combination, decreasing the tumor mass nearly 4-fold compared to controls. Weight-gain in each of the experimental cohorts at the end of the study was less than the control group, but the gain was significantly less in only two experimental groups (those receiving either EB1089 or Compound C plus Taxol). None of the animals became hypercalcemic, and their complete blood counts, serum electrolyte analyses, and liver and renal functions were all fairly similar and within the normal range. In summary, this combination of a vitamin D3 analog and Taxol has the potential to be a therapy for breast cancer.     

Growth-related oncogene produced in human breast cancer cells and regulated by Syk protein-tyrosine kinase

Syk, a nonreceptor type of protein tyrosine kinase widely expressed in hematopoietic cells, is a candidate suppressor gene in human breast cancer. Reduced expression of Syk protein is correlated with poor prognosis, while its overexpression can reduce the malignant phenotype of breast cancer cells. The mechanism of action of Syk remains unclear. In this study, we utilized low Syk-expressing, highly invasive MDA-MB-231 and high Syk-expressing, less invasive MCF-7 breast cancer cells to investigate the possibility that part of the functional effects of Syk are mediated by cytokines known to play roles in cell migration, invasion or metastasis. Using protein array technology, we determined that MDA-MB-231 cells secrete a number of cytokines known to regulate cellular growth and motility. One such cytokine, growth-related oncogene (GRO), has previously not been described in breast cancer. Of the compounds detected in the culture supernatant of MDA-MB-231, GRO was the only one that was significantly altered by modulation of Syk expression; overexpression of Syk caused a marked reduction in secreted levels of GRO. Conversely, downregulation of the relatively high levels of Syk produced in MCF-7 cells upregulated GRO secretion. At the mRNA level, overexpression of Syk in MDA-MB-231 differentially regulated the 3 GRO isotypes such that message levels of GROalpha and gamma were downregulated while that of GRObeta was not affected. Matrigel invasion assays demonstrated a link between Syk expression and resulting GRO activity in mediating the invasive potential of MDA-MB-231 cells. In summary, our findings provide evidence that human breast cancer cells express and secrete GRO and implicate this cytokine as an essential mediator of the antiinvasive properties of Syk tyrosine kinase.     

Antiestrogen regulation of cell cycle progression and cyclin D1 gene expression in MCF-7 human breast cancer cells

The molecular mechanisms by which antiestrogens inhibit breast cancer cell proliferation are not well understood. Using cultured breast cancer cell lines, we studied the effects of antiestrogens on proliferation and cell cycle progression and used this information to select candidate cell cycle regulatory genes that are potential targets for antiestrogens. Under estrogen- and serum-free conditions antiestrogens inhibited proliferation of MCF-7 cells stimulated with insulin. Cells were blocked at a point in G₁ phase. These effects are comparable with those in serum- and estrogen-containing medium and were also seen to a lesser degree in nude mice bearing MCF-7 tumors. Similar observations with other peptide mitogens suggest that the process inhibited by antiestrogens is common to estrogen and growth factor activated pathways. Other studies have identified G₁ cyclins as potential targets for growth factor and steroid hormone/steroid antagonist regulation of breast epithelial cell proliferation. In MCF-7 cells growing in the presence of fetal calf serum, cyclin D1 mRNA was rapidly down-regulated by steroidal and nonsteroidal antiestrogens by an apparently estrogen receptor mediated mechanism. Cyclin D1 gene expression was maximally inhibited before effects on entry into S phase and inhibition was therefore not merely a consequence of changes in cell cycle progression. Together with data on the effects of antiestrogens in serum-free conditions [1], these results suggest down-regulation of cyclin D1 by antiestrogens may be a general phenomenon in estrogen receptor-positive breast cancer cells, independent of culture conditions and class of antiestrogen. These observations are compatible with the hypothesis that reductions in cyclin D1 levels may mediate in part the action of antiestrogens in blocking entry of cells into S phase.     

Neuropilin-1 is differentially expressed in myoepithelial cells and vascular smooth muscle cells in preneoplastic and neoplastic human breast: a possible marker for the progression of breast cancer

The expression and distribution of neuropilin-1 (NRP-1) was examined in the samples of normal human breast tissues and in non-neoplastic and neoplastic areas of breast tissue removed for carcinoma using RT-PCR as well as conventional and tissue microarrays immunohistochemical analyses. The NRP-1 mRNA expression was significantly higher in neoplastic tissues as compared to normal breast samples. Immunohistochemically, the myoepithelial cells of the mammary ducts and lobules display positive reactions for NRP-1, whereas the inner ductal and lobular epithelial cell layers failed to react. The myoepithelial cells of ducts and lobules in both neoplastic and non-neoplastic tissue specimens displayed a stronger positive reaction for NRP-1 than those in the normal breast. A positive reaction for NRP-1, but with a gradual reduction in intensity, was observed in the myoepithelial cells of ducts with atypical epithelial hyperplasia and ductal carcinoma in situ (DCIS). The reaction was undetected or minimally detected in the areas of invasive carcinoma. NRP-1 positive immunolabeling was also localized in the vascular smooth muscle cells and in some endothelial cells of the blood vessels in normal, non-neoplastic and neoplastic breast tissue samples. In areas of breast carcinoma, NRP-1 immunolabeling was more prominent in both vascular smooth muscle cells and in some endothelial cells than in similar cells in normal breast. The specificity of the newly developed antibody for NRP-1 was confirmed by in situ hybridization with DIG-labeled PCR generated probe. These results suggest that NRP-1 may be a multiple function protein in human breast and may be involved in the induction of local invasiveness of neoplasia and angiogenesis and have direct relevance to the progression of breast cancer.     

Migration-promoting role of VEGF-C and VEGF-C binding receptors in human breast cancer cells

Vascular endothelial growth factor C (VEGF-C) is a lymphangiogenic factor over-expressed in highly metastatic, cyclooxygenase (COX)-2 expressing breast cancer cells. We tested the hypothesis that tumour-derived VEGF-C may play an autocrine role in metastasis by promoting cellular motility through one or more VEGF-C-binding receptors VEGFR-2, VEGFR-3, neuropilin (NRP)-1, NRP-2, and integrin alpha9beta1. We investigated the expression of these receptors in several breast cancer cell lines (MDA-MB-231, Hs578T, SK-BR-3, T-47D, and MCF7) and their possible requirement in migration of two VEGF-C-secreting, highly metastatic lines MDA-MB-231 and Hs578T. While cell lines varied significantly in their expression of above VEGF-C receptors, migratory activity of MDA-MB-231 and Hs578T cells was linked to one or more of these receptors. Depletion of endogenous VEGF-C by treatments with a neutralising antibody, VEGF-C siRNA or inhibitors of Src, EGFR/Her2/neu and p38 MAP kinases which inhibited VEGF-C production, inhibited cellular migration, indicating the requirement of VEGF-C for migratory function. Migration was differentially attenuated by blocking or downregulation of different VEGF-C receptors, for example treatment with a VEGFR-2 tyrosine kinase inhibitor, NRP-1 and NRP-2 siRNA or alpha9beta1 integrin antibody, indicating the participation of one or more of the receptors in cell motility. This novel role of tumour-derived VEGF-C indicates that breast cancer metastasis can be promoted by coordinated stimulation of lymphangiogenesis and enhanced migratory activity of breast cancer cells.     

Ectopic expression of herpes simplex virus-thymidine kinase gene in human non-small cell lung cancer cells conferred caspase-activated apoptosis sensitized by ganciclovir

Human non-small cell lung cancer (NSCLC) cells were transfected with recombinant prodrug herpes simplex virus type I thymidine kinase (HSV-tk) cDNA, and the selected clones underwent apoptosis in response to induction by antiviral ganciclovir (GCV). The efficiency of GCV-induced growth inhibition and the extent of the bystander effect were associated with the expression level of HSV-TK in stable transfectants. Development in the HSV-tk/GCV system toward cell death was initiated with cell-cycle accumulation at S and G(2)/M phases, immediately followed by the appearance of sub-G(0)/G(1) cells after drug exposure. To investigate the regulation of cell-cycle modulators during drug treatment, we analyzed release of the apoptosis initiator cytochrome c and activation of the downstream effectors caspase-9, caspase-3 and poly(ADP-ribose)polymerase 16 hr after GCV sensitization, followed by transient escalation of tumor-suppressor p53 and cell-cycle modulators cyclin A and B(1) before committing to programmed cell death. Furthermore, tumor regression was proportional to the degree of ectopic expression of the transferred HSV-tk gene. Our results demonstrate that the HSV-tk/GCV system effectively inhibits the proliferation of NSCLC cells in vitro and in vivo through potent induction of apoptosis, thus providing a rationale for further development.     

Cathepsin D expression by cancer and stromal cells in breast cancer: an immunohistochemical study of 1348 cases

This study was aimed at investigating the influence of cathepsin D (CD) expression by cancer cells and stromal cells on breast cancer prognosis. This is a study of 1348 nodepositive (NPBC) and nodenegative (NNBC) breast cancers diagnosed between 1980 and 1986 and with a minimum followup of 5.2years. CD expression was assessed by immunohistochemistry on archival material using a polyclonal antibody. The expression by cancer and stromal cells was assessed separately and correlated with distant metastasis free (DMFS) and overall survival (OS). Cancer cells expressed CD (more than 10% cells expressing CD) in 38.9% of cases and reactive stromal cells in 43.6%. CD expression by reactive stromal cells, and not cancer cells, correlated with several factors of poor prognosis by cancer cells. A strong association was also found with expression of other proteases (stromelysin3, gelatinase A, and urokinase Plasminogen Activator) by these same reactive stromal cells. CD expression by cancer cells did not predict DMFS or OS but, by univariate analysis, CD expression by reactive stromal cells was associated with earlier recurrence and shorter survival in NNBC (p = 0.0425) and NPBC patients submitted to adjuvant chemotherapy (p = 0.0234). However, CD expression by reactive stromal cells remained a significant predictor of recurrence by multivariate analyses only in a subgroup of NPBC submitted to adjuvant chemotherapy. Overall, those data support the concept that proteases produced by reactive stromal cells are under cancer cell stimulation and that CD by stromal cells, and not cancer cells, influences the prognosis, but only in a subgroup of patients with breast cancer.     

酒石酸长春瑞滨脂质微球注射液对荷人乳腺癌裸鼠肿瘤生长的影响

目的: 研究酒石酸长春瑞滨脂质微球注射液(NVB-lip)对荷人乳腺癌裸鼠肿瘤生长的影响。方法: 35只雌性BALB/c-nu裸鼠,随机分为NVB-lip高(10 mg/kg)、中(5 mg/kg)、低(2.5 mg/kg)剂量组,阳性对照组(酒石酸长春瑞滨注射液,5 mg/kg)和阴性对照组(脂质化空白溶液),每组7只。给裸鼠接种人乳腺癌BCAP-37瘤株,待成瘤后,每只动物每次按0.20 mL经尾静脉注射给药,间隔3~4 d注射1次,每周注射2次,共注射6次。在第1次注射后第4、7、11、14、18和23天时分别称小鼠体质量和测量肿瘤体积,计算得出相对肿瘤体积、相对肿瘤增殖率和肿瘤抑制率。结果: 与阴性对照组相比,各组荷瘤裸鼠体质量差异均无统计学意义(P均>0.05)。NVB-lip各剂量组的相对肿瘤体积和相对肿瘤增殖率显著减小,肿瘤抑制率显著增大,差异均有统计学意义(P<0.01)。结论: NVB-lip在2.5~10 mg/kg范围内抑瘤作用明显,具有可开发潜力。     

Curcumin analog B14 has high bioavailability and enhances the effect of anti‐breast cancer cells in vitro and in vivo

Curcumin has a variety of anticancer properties, but low bioavailability prevents its use in chemotherapeutic applications. To address this problem, we tested the efficacy of the synthetic curcumin analog B14 in breast cancer cells and explored the mechanism by which B14 inhibits proliferation and metastasis of breast cancer cells. We used the breast cancer cell line MCF‐7, MDA‐MB‐231 to study the anticancer effects of B14 and assessed cell viability, cell migration and invasion, cell cycle, and apoptosis, in addition, the antitumor effect of B14 in vivo was examined in mice bearing MDA‐MB‐231 cells. We found that, as the concentration of B14 increased, cell viability decreased in a dose‐dependent manner. Compound B14 exerted the best antitumor activity and selectivity for MCF‐7 and MDA‐M‐231 cells (IC₅₀ = 8.84 μmol/L and 8.33 μmol/L, respectively), while its IC₅₀ value for MCF‐10A breast epithelial cells was 34.96 μmol/L. B14 has been shown to be a multi‐targeted drug that alters the expression of cyclin D1, cyclin E1, and cyclin‐dependent kinase 2 (CDK2), and ultimately induces G1 phase cell cycle arrest. At the same time, B14 activates the mitochondrial apoptosis pathway in breast cancer cells. Furthermore, B14 was more effective than curcumin in inhibiting cell migration, invasion, and colony formation. In tumor‐bearing mice, analog B14 significantly reduced tumor growth and inhibited cell proliferation and angiogenesis. The pharmacokinetic test found that B14 was more stable than curcumin in vivo. Our data reveal the therapeutic potential of the curcumin analog B14 and the underlying mechanisms to fight breast cancer cells.     

Flubendazole,FDA-approved anthelmintic,targets breast cancer stem-like cells

Cancer stem-like cell (CS-like cell) is considered to be responsible for recurrence and drug resistance events in breast cancer, which makes it a potential target for novel cancer therapeutic strategy. The FDA approved flubendazole, has been widely used in the treatment of intestinal parasites. Here, we demonstrated a novel effect of flubendazole on breast CS-like cells. Flubendazole inhibited breast cancer cells proliferation in dose- and time-dependent manner and delayed tumor growth in xenograft models by intraperitoneal injection. Importantly, flubendazole reduced CD44^high/CD24^low subpopulation and suppressed the formation of mammosphere and the expression of self-renewal related genes including c-myc, oct4, sox2, nanog and cyclinD1. Moreover, we found that flubendazole induced cell differentiation and inhibited cell migration. Consistently, flubendazole reduced mesenchymal markers (β-catenin, N-cadherin and Vimentin) expression and induced epithelial and differentiation marker (Keratin 18) expression in breast cancer cells. Mechanism study revealed that flubendazole arrested cell cycle at G2/M phase and induced monopolar spindle formation through inhibiting tubulin polymerization. Furthermore, flubendazole enhanced cytotoxic activity of conventional therapeutic drugs fluorouracil and doxorubicin against breast cancer cells. In conclusion, our findings uncovered a remarkable effect of flubendazole on suppressing breast CS-like cells, indicating a novel utilization of flubendazole in breast cancer therapy.     

Exogenous morphine inhibits human gastric cancer MGC- 803 cell growth by cell cycle arrest and apoptosis induction

Morphine is not only an analgesic treating pain for patients with cancer but also a potential anticancer drug inhibiting tumor growth and proliferation. To gain better insight into the involvement of morphine in the biological characteristics of gastric cancer, we investigated effects on progression of gastric carcinoma cells and the expression of some apoptosis-related genes including caspase-9, caspase-3, survivin and NF-κB using the MGC-803 human gastric cancer cell line. The viability of cells was assessed by MTT assay, proliferation by colony formation assay, cell cycle progression and apoptosis by flow cytometry and ultrastructural alteration by transmission electron microscopy. The influences of morphine on caspase-9, caspase-3, survivin and NF-κB were evaluated by semi-quantitative RT-PCR and Western blot. Our data showed that morphine could significantly inhibit cell growth and proliferation and cause cell cycle arrest in the G2/M phase. MGC-803 cells which were incubated with morphine also had a higher apoptotic rate than control cells. Morphine also led to morphological changes of gastric cancer cells. The mechanism of morphine inhibiting gastric cancer progression in vitro might be associated with activation of caspase-9 and caspase-3 and inhibition of survivin and NF-κB.