The anti-cancer peptide, PNC-27, induces tumor cell lysis as the intact peptide

Purpose

PNC-27, a peptide that contains an HDM-2-binding domain from p53 attached to a membrane-penetrating peptide on its carboxyl terminal end, is cytotoxic to cancer, but not normal, cells. It forms transmembrane pores in the cancer cell membrane. Our purpose is to determine if the whole peptide or critical fragments induce pore formation in cancer cells.

Methods

We have prepared PNC-27 with a green fluorescent label on its amino terminus and a red fluorescent label on its carboxyl terminus and treated MCF-7 breast cancer cells and untransformed MCF-10-2A breast epithelial cells with this double-labeled peptide to determine if combined yellow fluorescence occurs in the membrane of the cancer cells during cancer cell killing.

Results

At 30 min, there is significant combined punctate yellow fluorescence, indicative of intact peptide, in the cell membrane of cancer cells that increases during cancer cell lysis. MCF-10-2A cells show initial (30 min) uniform combined yellow membrane fluorescence that subsequently disappears. Unlike the cancer cells, these untransformed cells remain viable.

Conclusions

PNC-27 induces cancer cell membrane lysis by acting as the whole peptide, not fragments. The punctate yellow fluorescence is due to interaction of PNC-27 with intramembrane targets of MCF-7 cells that do not exist in the membrane of the untransformed cell line. This interaction increases the lifetime of PNC-27. Absence of these targets in the membranes of the untransformed MCF-10-2A cells results in initial uniform fluorescence of the double-labeled peptide in their membranes after which the peptide is degraded.     

Phase I clinical trial of vaccination with LY6K-derived peptide in patients with advanced gastric cancer

Background

Lymphocyte antigen 6 complex locus K (LY6K) has been identified as a tumor-associated antigen in lung cancers and esophageal squamous cell carcinomas. The immunogenicity of LY6K-177 peptide vaccine therapy has been demonstrated in patients with advanced esophageal cancer. This study extends this treatment to gastric cancer.

Methods

LY6K expression in clinical samples obtained from gastric cancer patients was examined by immunochemistry. As a phase I clinical trial, the safety and immunogenicity of LY6K-177 peptide vaccine emulsified with Montanide ISA 51 was evaluated in six patients with unresectable advanced gastric cancer. LY6K-177 peptide (1 mg in 1 ml sterile saline) was emulsified with incomplete Freund’s adjuvant (1 ml) and intracutaneously administered to the inguinal region or axilla. One treatment course comprised four vaccinations, performed weekly for the first and second treatment courses and biweekly for the third treatment course.

Results

LY6K expression was confirmed in 85 % of gastric cancer tissues. Induration and redness at the vaccination site (grade I), possibly a delayed-type hypersensitivity reaction, was observed in all patients; however, no systemic toxicology was identified in any patient throughout the observation period. Three of the six patients had stable disease, and a tumor contraction effect was observed in one patient.

Conclusions

LY6K was expressed in 85 % of observed gastric cancers. Vaccination with LY6K-177 peptide/Montanide ISA 51 appeared to be tolerated by advanced gastric cancer patients, and moreover anticancer efficacy was suggested. This trial was registered with ClinicalTrial.gov (no. NCT00845611).     

The safety and efficacy of cisplatin plus gemcitabine in recurrent ovarian cancer

Background

The activity and synergy for the combination treatment of cisplatin and gemcitabine has been identified in a variety of human tumor cells, including ovarian cancer cells, and has been widely approved for the treatment of non-small cell lung cancer, pancreatic cancer and biliary tract cancer. As the gastrointestinal symptoms with cisplatin therapy are commonly considered to negatively affect the quality of life of patients more than those experienced with carboplatin therapy, carboplatin is generally preferred over cisplatin in combination therapy. This study evaluated the safety and efficacy of cisplatin plus gemcitabine in patients with recurrent ovarian cancer.

Methods

Patients with recurrent ovarian, peritoneal or fallopian tube cancer, who had failed with multiple other chemotherapy agents, including platinum, received cisplatin (30 mg/m²) plus gemcitabine (750 mg/m²) on days 1 and 8 of every 28 days for between 1 and 4 cycles.

Results

In total, 18 patients were treated with cisplatin and gemcitabine between 2006 and 2011. There were 1 complete and 5 partial responses, producing an overall response rate of 33.4 %. Median overall survival was 11.0 months. Grade 4 neutropenia and thrombocytopenia were seen in 11.1 and 22.2 % of patients, respectively. Non-hematological toxicity was less than Grade 1.

Conclusions

Non-hematological toxicity with combined cisplatin and gemcitabine therapy was considered tolerable and did not impede patient quality of life. However, this drug combination should be monitored for hematologic toxicity.     

A novel peptide (Thx) homing to non-small cell lung cancer identified by ex vivo phage display

Aim

To identify linear peptide homing to non-small cell lung cancer (NSCLC) tumor cells using ex vivo phage display method.

Materials and methods

Twenty-six clinical patient samples were used to identify linear homing peptide, which was exposed to NSCLC cell cultures and control cell lines to determine cell binding affinity and cell localization. Also, ex vivo biodistribution was analyzed using tumor-bearing mice.

Results

The panning yielded peptide enrichment with a core motif ^A/_SRXPXXX. Based on this, an amino acid sequence, ARRPKLD, was selected for characterization and named Thx-peptide. The in vitro binding properties of Thx-peptide demonstrated selectivity toward NSCLC. Internalization assays showed that Thx-Alexa and fluorescein conjugates were located in a subset of perinuclearly located lysosomes of tumor cells. Thx-peptide appeared with fluorescein-labeled peptide and peptide-DTPA-chelator complex in adenocarcinoma xenografts in mice.

Conclusion

Thx shows promise for targeted imaging and drug delivery.     

A novel bis-indole destabilizes microtubules and displays potent in vitro and in vivo antitumor activity in prostate cancer

Purpose

Microtubules are one of the most useful subcellular targets in chemotherapy. We identified a novel indole, (3-(1H-indol-2-yl)phenyl)(1H-indol-2-yl)methanone (15), that inhibits tubulin action and exhibits potent antitumor activity in various preclinical models.

Methods

In vitro cancer cell growth inhibition was measured by SRB or MTT assay in human cancer cell lines. Apoptosis induced by 15 was examined in LNCaP and PC-3 cells. Effects of 15 on cell cycle distribution and tubulin were investigated via in vitro models. In vivo toxicity and xenograft efficacy studies were conducted in mice.

Results

Indole 15 inhibited the in vitro growth of a number of human cancer cell lines, including drug-resistant cell lines that over-express P-glycoprotein, multidrug resistance-associated proteins, and breast cancer resistance protein with IC₅₀ values in the range of 34?C162?nM. Nanomolar concentrations of the compound caused down-regulation of bcl-2, induced PARP cleavage, and induced apoptosis in both LNCaP and PC-3 prostate cancer cells, as confirmed by anti-histone ELISA and DNA laddering. In vitro studies revealed that the compound inhibited polymerization of purified tubulin and induced a strong and concentration-dependent G₂M arrest in PC-3 cells. In vivo studies in immunodeficient mice bearing PC-3 tumor xenografts showed that the compound effectively inhibited tumor growth.

Conclusions

The potent in vitro and in vivo antitumor activities of this novel indole suggest that drugs with this novel chemical scaffold might be developed for treatment of drug-resistant prostate cancer.     

Supplementation of fish oil augments efficacy and attenuates toxicity of 5-fluorouracil in 1,2-dimethylhydrazine dihydrochloride/dextran sulfate sodium-induced colon carcinogenesis

Purpose

5-Fluorouracil (5-FU) is used for the treatment of colorectal cancer, but has low therapeutic response rate and severe side effects. Recently, fish oil (FO) rich in n-3 polyunsaturated fatty acids has been preferred to chemosensitize tumor cells to anticancer drugs. Therefore, the current study is designed to evaluate chemotherapeutic efficacy and toxicity profile of 5-FU in combination with FO in 1,2-dimethylhydrazine dihydrochloride/dextran sulfate sodium (DMH/DSS)-induced colon cancer model.

Methods

The therapeutic efficacy of 5-FU along with FO was analyzed through assessment of survival rate, tumor burden, volume, serum sialic acid levels, cytokeratin 19 (CK19) expression and index of cell proliferation such as cell cycle progression. Toxicological aspects were evaluated by standard functional and structural parameters related to spleen, gastrointestinal, liver and kidney.

Results

In the present study, 5-FU in combination with FO increased the survival rate in carcinogen-treated animals. Synergism of 5-FU and FO was also reflected in significant inhibition in tumor growth and serum sialic acid levels in DMH/DSS model. Moreover, the combination dosage significantly augmented the inhibition of cell cycle progression, as shown by CK19 expression. Additionally, FO ameliorated hematologic depression, gastrointestinal, hepatic and renal toxicity caused by 5-FU as substantiated by a marked improvement in structural and functional alterations of these organs.

Conclusion

The supplementation of FO is potentially a promising option for increasing the therapeutic potential and mitigating the side effects of 5-FU.     

Use of KW-2189, a DNA Minor Groove-Binding Agent, in Patients with Hepatocellular Carcinoma: A North Central Cancer Treatment Group (NCCTG) Phase II Clinical Trial

Background

Hepatocellular carcinoma (HCC) is a common cancer in certain portions of the world. Currently no effective therapies exist for patients with advanced or metastatic HCC. KW-2189, a DNA minor groove-binding agent, has shown promising activity against HCC in preclinical evaluations.

Methods

A phase II study was conducted to evaluate the activity of KW-2189 in patients with histologic or cytologic confirmed advanced or metastatic HCC who had no prior systemic therapy. Patients received KW-2189 at a dose of 0.5 mg/m² administered on day 1 of a 6-week cycle. The primary endpoint of the trial was objective regression. Other endpoints included toxicity, disease-free survival, and overall survival.

Results

Due to hematologic toxicity the dose of KW-2189 was reduced to 0.375 mg/m² after 11 patients had been enrolled into the trial. Due to continued significant hematologic toxicity in the next five patients enrolled at the lower dose the trial was closed to accrual. Two responses were seen in patients enrolled at the higher dose, including one sustained CR.

Conclusion

KW-2189 showed evidence of anti-tumor activity in HCC. However, because of significant and prolonged hematologic toxicity, when given as a single dose every 6 weeks, further development of this drug in HCC is not possible. Further exploration of DNA minor groove-binding agents in the treatment of HCC appears warranted.     

A multicenter phase II study of belotecan, a new camptothecin analogue, in elderly patients with previously untreated, extensive-stage small cell lung cancer

Purpose

Belotecan is a new camptothecin analogue and a potent topoisomerase I inhibitor. The aim of this phase II study was to investigate the efficacy and toxicity of belotecan in previously untreated elderly patients with small cell lung cancer (SCLC).

Methods

A total of 26 patients, aged ≥65 years, with previously untreated, extensive-stage SCLC were enrolled in the study. Belotecan was administered by daily intravenous infusion at 0.5 mg/m²/day for 5 consecutive days every 3 weeks.

Results

The overall response rate and disease control rate of chemotherapy on an intention-to-treat basis were 35 and 54 %, respectively. The median overall survival was 6.4 months, and the median time to progression was 2.8 months. The most common toxicity was hematologic. Grade 3 or 4 neutropenia occurred in 80.8 % of patients, and grade 3 or 4 thrombocytopenia in 15.3 %. Non-hematologic toxic effects of grade 3 or 4 were uncommon.

Conclusion

Belotecan had modest efficacy and well-tolerated toxicity in previously untreated, elderly SCLC patients. Single belotecan could be a promising treatment option, considering its lower toxicity in elderly patients who are unsuitable candidates for platinum plus etoposide chemotherapy.     

Toxicity against gastric cancer cells by combined treatment with 5-fluorouracil and mitomycin c: implication in oxidative stress

Purpose

Combined chemotherapy of 5-fluorouracil (5FU) and mitomycin c (MMC) is clinically used for gastric cancer, but the precise conditions and molecular mechanism of these agents when used together remain unclear. We examined the administration sequence of combining 5FU with MMC to maximize toxicity against a human gastric cancer cell line, and then investigated the possible molecular mechanisms underlying the observed toxic effects.

Methods

Human gastric cancer MKN45 cells were treated with a combination of 5FU and MMC, and the changes in cell viability and apoptosis-related proteins were determined by a tetrazolium dye-based cytotoxicity assay and Western blot analysis, respectively. The intracellular levels of reactive oxygen species (ROS) were monitored using a fluorescent probe or by a cytochrome c reduction assay.

Results

Pretreatment for 24 h with 5FU augmented the toxic effect of MMC in MKN45 cells. The synergic effect was mediated mainly via ROS formation and the p53-dependent apoptotic pathway, leading to mitochondrial dysfunction and caspase activation. In vitro experiments using extracts of the treated cells showed superoxide anion generation in a redox cycle of MMC, involving alterations in superoxide dismutase.

Conclusions

Pretreatment with 5FU enhanced the MMC-induced toxicity against gastric cancer cells via alterations in antioxidant enzymes with resulting ROS generation. This observation will need confirmation in the clinical setting.     

Phase II randomized trial of carboplatin and gemcitabine with or without dexamethasone pre-treatment in patients with Stage IV non-small cell lung cancer

Purpose

Pre-clinical and early-phase clinical studies have demonstrated that dexamethasone (DEX) administration prior to chemotherapy reduces toxicity and enhances efficacy in the treatment of cancer. We undertook a randomized, phase II multi-institutional trial to evaluate these effects in patients with Stage IV non-small cell lung cancer.

Methods

Patients were treated with carboplatin on day 1 and gemcitabine on days 1 and 8 every 21 days, for up to 6 cycles. Patients were randomized not to receive (Arm 1, n = 25) or to receive (Arm 2, n = 31) DEX orally for 4 days prior to chemotherapy on days 1 and 8. The primary endpoint was the incidence/course of grade 3 and 4 hematologic toxicity. Secondary endpoints included efficacy [response and overall survival (OS)] and evaluation of the Glasgow Prognostic Score (GPS), based on C-reactive protein and albumin levels, to predict survival and toxicity.

Results

The incidence/course of grade 3 and 4 hematologic toxicity was significantly reduced in Arm 2 (DEX) versus Arm 1 (no DEX): neutrophils = 13 versus 40 % (p = 0.009) and platelets = 23 versus 44 % (p = 0.03). Response rates and OS were higher in Arm 2 versus Arm 1: 8/31 versus 2/25 (partial response, p = ns) and 378 versus 291 days (p = ns). The GPS significantly predicted survival OS (p = 0.04) but not toxicity.

Conclusions

Pre-treating patients with DEX is a safe, effective, and economic method of reducing the hematologic toxicity of carboplatin and gemcitabine. Our data suggest efficacy may also be enhanced by DEX pre-treatment.     

肺癌新肿瘤标志物periplakin的筛选研究(英文)

Objective: The aim of this study was to use lung cancer targeting binding polypeptide ZS-9 to screen cDNA library of human lung cancer and obtain ZS-9 specific ligand to confirm tumor marker of non small-cell lung cancer. Methods: Artificially synthesize biotin labeled peptide ZS-9, anchored ZS-9 in the enzyme label plate coupled by avidin, used ZS-9 as probe to screen cDNA library of human lung cancer, after screening, obtained bacteriophage clone specifically binding with anchored polypeptide ZS-9. Extracted plasmid of bacteriophage and performed sequencing after amplified by PCR. Results: It was demonstrated by bioinformatic analysis on the sequence of ligand binded by lung cancer specific peptide ZS-9 that the ligand was the cytoskeletal protein periplakin on the surface of lung cancer cells, suggesting that periplakin might be a new marker for non-small-cell lung cancer in lung cancer. Conclusion: Use specific lung cancer binding peptide to screen new tumor marker periplakin in lung cancer and further studies on its biologic functions in genesis and development of lung cancer are still needed.     

Identification of a novel short peptide seal specific to CD59 and its effect on HeLa cell growth and apoptosis

Background

In the past, some small peptide ligands identified by phage display technologies have successfully been used in early cancer diagnostics and therapy. In the present study, a novel CD59-binding peptide was identified and its effect on HeLa cell growth and apoptosis was investigated.

Methods

A phage display library was screened yielding a novel short peptide, sp22, that specifically binds to CD59, a protein that shows altered expression in various diseases, including cancer. The effect of ectopic sp22 administration and exogenous sp22 expression on the growth and apoptosis of HeLa cells was assessed. For the latter, we constructed and transfected a sp22-pIRES vector into HeLa cells.

Results

Our results show that sp22 peptides can inhibit the level of CD59 mRNA expression, down-regulate Bcl-2 expression, increase Fas and caspase-3 expression, increase the level of cytolysis, and increase the apoptosis of HeLa cells. In contrast, sp22 peptides had no effect on normal human embryonic lung (HEL) cells exhibiting a relatively low CD59 expression level. Compared to untransfected HeLa cells, exogenously sp22 expressing HeLa cells showed a reduced CD59 expression, an increased complement-mediated lysis, a decreased cellular survival ratio, and an increase in apoptotic cells.

Conclusion

The newly identified sp22 peptide can, in a dose-dependent manner, inhibit CD59 expression. Concomitantly, sp22 can increase complement-mediated lysis and apoptosis signals. This information may be instrumental for the design of novel therapeutic strategies.     

Expression of a novel peptide derived from PCNA damages DNA and reverses cisplatin resistance

Background

An 8 amino acid peptide sequence derived from proliferating cell nuclear antigen (PCNA) has been shown to effectively kill several breast cancer and neuroblastoma cell lines when added exogenously to cell cultures.

Methods

In this study, the expression of the 8 amino acid peptide sequence (caPeptide) was placed under control of a tetracycline responsive promoter in MDA-MB-231 cells.

Results

Endogenous expression of the peptide resulted in an increase in genomic DNA damage. CaPeptide induction combined with treatment of sublethal doses of cisplatin resulted in a marked increase in death of the cisplatin-resistant MDA-MB-231 cell line. CaPeptide was found to interact with POLD3, one of the subunits of DNA polymerase delta necessary for binding to PCNA.

Conclusion

These results suggest an important line of inquiry into the possible role that caPeptide might play in the reversal of cisplatin resistance in breast and other cancers. This is of particular interest in those cancers where cisplatin is the first line of chemotherapy and where the acquisition of resistance is a common malady.     

Effects of a human compact anti-ErbB2 antibody on gastric cancer

Background

Gastric cancer represents one of the most common causes of cancer deaths worldwide. Overexpression of ErbB2, a tyrosine kinase receptor involved in the pathogenesis of several human cancer types, has been reported also in gastric cancer. Thus, the inhibition of ErbB2 signal transduction pathways by the use of human antibodies could be a valuable strategy for the therapy of this type of cancer.

Methods

We tested for the first time the antitumor effects on gastric cancer cells of Erb-hcAb, a novel fully human compact antibody, prepared in our laboratory, which targets a different epitope of ErbB2 with respect to trastuzumab, the only anti-ErbB2 antibody currently in clinical use for both breast and gastric cancer therapy.

Results

Herein we demonstrate that the in vitro and in vivo growth of gastric cancer cells is efficiently inhibited by Erb-hcAb, which shows antitumor effects on the NCI-N87 cell line more potent than those observed for trastuzumab.

Conclusions

Erb-hcAb could be a promising candidate in the immunotherapy of gastric cancer as it combines the antiproliferative effect associated with the inhibition of ErbB2 signaling on tumor target cells with the ability to induce antibody-dependent cellular cytotoxicity.     

Lenalidomide in solid tumors

Background

Lenalidomide is a thalidomide analogue with immunomodulatory and anti-angiogenic properties that include altering cytokine production, activating T cells, and augmenting natural killer cell function. Lenalidomide is approved by the U.S. Food and Drug Administration (FDA) for single-agent treatment of myelodysplastic syndromes associated with a 5q deletion and as a combination therapy with dexamethasone for the treatment of multiple myeloma.

Methods

All prospective phase I–III clinical trials and preclinical data published until October 2011 and relevant literature were reviewed.

Results

In phase I and/or II studies of single-agent lenalidomide in patients with advanced cancer, responses were reported in patients with prostate, thyroid, hepatocellular, pancreatic, and renal cancer and melanoma. The most common toxicities were hematologic, and in the first clinical trials, thrombotic events were noted. When anticoagulation prophylaxis and exclusion of patients with a history of thrombosis were implemented, thrombotic complications became uncommon.

Conclusion

Monitoring of blood counts and for evidence of thromboembolic events is essential for patients treated with lenalidomide. Ongoing trials of lenalidomide combination therapy offer a treatment option for patients with advanced cancer and will better define the role of lenalidomide in solid tumors.     

人胃癌裸鼠移植瘤中标记滞留细胞的初步鉴定(英文)

Objective:This study has investigated the existence of label-retaining cell and its distribution in gastric cancer,in the hope that this information will assist investigations on gastric cancer stem cells.Methods:The gastric carcinoma cell line BGC-823 was labeled with BrdU in vitro and then engrafted into the right axilla of nude mice,which developed tumors.Label-retaining cells were quantified by immunohistochemical methods.Results:BrdU positive cells constituted about 96%of the cells in xenograft tumors after 10 days.Subsequently,BrdU positive cells gradually decreased,at the 80th day,labelretaining cells steadily occupied about 0.5%.This set of population cell localized in the margin of cancer nests,which had no difference in cellular morpha.Conclusion:The study demonstrates the presence of label-retaining cells in human gastric cancer xenografts in nude mice and the label-retaining cells may be related with cancer stem cells,which are most likely the cause for spread,metastasis and recurrence.     

Clinical predictors of severe toxicity in patients treated with combination chemotherapy with irinotecan and/or oxaliplatin for metastatic colorectal cancer

Introduction

Little has been published regarding clinical predictors of severe toxicity in patients with metastatic colorectal cancer (CRC) treated with combination chemotherapy (CT) with oxaliplatin and/or irinotecan.

Material and Methods

We analyzed retrospectively 142 patients treated between 1996 and 2004 in our center with these regimes with regards to grade 3–4 toxicity and overall survival (OS) rates. Köhne's prognostic classification could be applied in all patients.

Results

Köhne classification: good (54.2%), intermediate (26.8%), and poor prognosis (19%). 50.4% received irinotecan-based CT. Median number of cycles 6 with a total response rate of 38.9%. 23.2% stopped first-line CT due to toxicity. 50.7% suffered grade 3–4 toxicity: digestive (28.2%), hematologic (19.7%), and fatigue (25.4%). 7.7% episodes of neutropenic fever with 4.9% toxic deaths. 70.9% of grade 3–4 episodes occurred in the first four cycles. Median follow-up of 33.9 mo; median OS of 15.9 mo. For Köhne classification: good (20 mo), intermediate (15.8 mo), and poor (6.8 mo). Toxicity analysis: female sex and age>70 yr predicted higher overall grade 3–4 toxicity, with no differences in CT efficacy; age>70 yr and PS>1 predicted higher grade 3–4 fatigue. No relationship could be found between baseline laboratory characteristics and higher toxicity, except baseline hemoglobin and grade 3–4 hematologic toxicity.

Conclusions

Female and elderly patients have a higher grade 3–4 toxicity rate when treated with combination CT with oxaliplatin or irinotecan. Prognostic classifications such as Köhne's can help differentiate subgroups of patients who benefit little with the use of combination CT.     

Phase II study of S-1 and docetaxel for previously treated patients with locally advanced or metastatic non-small cell lung cancer

Purpose

The purpose of the present phase II study was to evaluate both the efficacy and toxicity of the combination of S-1 and docetaxel in previously treated patients with locally advanced or metastatic non-small cell lung cancer.

Methods

Thirty-eight previously treated patients with non-small cell lung cancer were treated with S-1 (80 mg/m², days 1–14, oral) and docetaxel (40 mg/m², day 1, intravenous) every 3 weeks.

Results

No complete response was observed, and seven patients had a partial response, yielding an overall response rate of 18.4% (95% CI, 7.7–34.3%). The median overall survival time and 1-year overall survival rate were 16.1 months and 60%, respectively. The median progression-free survival time was 4.4 months. Myelosuppression was the main toxicity with grade 3 or 4 neutropenia and leukopenia in 50 and 21%, respectively. There was no irreversible toxicity in this study.

Conclusions

The combination of S-1 and docetaxel is well tolerable and has substantial activity for patients with locally advanced or metastatic non-small cell lung cancer. A phase III trial comparing docetaxel with or without S-1 would warrant further investigation.     

Human antimicrobial protein hCAP18/LL-37 promotes a metastatic phenotype in breast cancer

Introduction

Human cathelicidin antimicrobial protein, hCAP18, and its C-terminal peptide LL-37 is a multifunctional protein. In addition to being important in antimicrobial defense, it induces chemotaxis, stimulates angiogenesis and promotes tissue repair. We previously showed that human breast cancer cells express high amounts of hCAP18, and hypothesised that hCAP18/LL-37 may be involved in tumour progression.

Methods

hCAP18 mRNA was quantified in 109 primary breast cancers and compared with clinical findings and ERBB2 mRNA expression. Effects of exogenous LL-37 and transgenic overexpression of hCAP18 on ErbB2 signalling were investigated by immunoblotting using extracts from breast cancer cell lines ZR75-1 and derivatives of MCF7. We further analysed the impact of hCAP18/LL-37 on the morphology of breast cancer cells grown in soft agar, on cell migration and on tumour development in severe combined immunodeficiency (SCID) mice.

Results

The expression of hCAP18 correlated closely with that of ERBB2 and with the presence of lymph node metastases in oestrogen receptor-positive tumours. hCAP18/LL-37 amplified Heregulin-induced mitogen-activated protein kinase (MAPK) signalling through ErbB2, identifying a functional association between hCAP18/LL-37 and ErbB2 in breast cancer. Treatment with LL-37 peptide significantly stimulated the migration of breast cancer cells and their colonies acquired a dispersed morphology indicative of increased metastatic potential. A truncated version of LL-37 competitively inhibited LL-37 induced MAPK phosphorylation and significantly reduced the number of altered cancer cell colonies induced by LL-37 as well as suppressed their migration. Transgenic overexpression of hCAP18 in a low malignant breast cancer cell line promoted the development of metastases in SCID mice, and analysis of hCAP18 transgenic tumours showed enhanced activation of MAPK signalling.

Conclusions

Our results provide evidence that hCAP18/LL-37 contributes to breast cancer metastasis.