The expression profiles of miRNAs in the progression of prostate cancer from high-grade prostatic intraepithelial neoplasia to metastatic diseases

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Background: The epigenetic regulation by miRNA plays an important role in tumor progression of prostate cancer (PCa). Methods: The expression data of 1054 miRNAs from TCGA were applied to identify relevant miRNAs associated with tumor progression (i.e. miR-210, miR-375, miR-378, miR-345, miR-143 miR-183 and miR-98). miRNA were isolated by miRNeasy FFPE kit (Qiagen, Hilden, Germany) from paraffin-embedded tissues of prostate specimens with PCa, HGPIN and normal tissues. Early-stage PCa was defined as PCa with pT2 tumor stage, Gleason score < = 7a (3+4) and PSA level < 10 ng/ml. PCa with pT3/4 or Gleason > 7a was defined as advanced PCa. PCa with pN1 were considered as metastatic diseases. Additionally, 3 cases with castration-resistant prostate cancer (CRPC) were considered. Quantitative miRNA expression data were acquired and analyzed using a real-time TaqMan-based PCR. ANOVA analyses were performed to evaluate the expression of miRNAs between HGPIN, Normal and PCa tissues. The small nuclear U6 RNA was used as an endogenous control Results: ANOVA analysis revealed a significant variation in expression of all miRNAs among groups. The expression level of miR-183 and miR-375 increased with the tumor progression. miR-143, miR-375-3p were inversely correlated with the tumor progression. miR-210 and miR-183 were significantly overexpressed in metastatic diseases compared to non-metastatic diseases (FDR < 0.01), whereas the expression level of miR-378-3p was lower in metastatic diseases than in organ-confined PCa. The expression of miR-98 was lower in PCa compared to normal tissues. In silico analysis, the down-regulation of miR-98 and miR-345-5p seems to activate the HIF-1 signaling pathway initiating the up-regulation of miR-210 that interact with genes related to cell cycle, RNA transcription, homologous recombination and non-homologous end-joining. Conclusions: Our data reveal epigenetic regulations of miRNA, which are associated with transition from normal tissues to HGIPN, from HGPIN to early-stage PCa, and early-stage PCa to advanced PCa. Advanced PCa represents the first stage of metastatic diseases.

Enhanced overexpression of hypoxia-related miRNA-210 in primary tumor of metastatic prostate cancer

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Background: miR-210 is a known transcriptional target of the hypoxia-responsive HIF-1α signaling pathway. However, the association between the expression of miR-210 and the tumor progression in prostate cancer (PCa) remains unclear. Methods: We isolated miRNA by miRNeasy FFPE kit (Qiagen, Hilden, Germany) from paraffin-embedded tissues of 87 prostate specimens with adenocarcinoma of the prostate cancer in different tumor stages, with high-grade prostatic intraepithelial neoplasia (HGPIN) and normal tissues. Organ-confined PCa was defined as PCa with pT2 tumor stage, Gleason score ≤ 7a and PSA level < 10 ng/ml. PCa with pT3/4 or Gleason > 7a was defined as advanced PCa. PCa with pN1 were considered as metastatic diseases. Additionally, 3 cases with castration-resistant prostate cancer (CRPC) were considered. Quantitative miR-210 expression data were acquired and analyzed using a real-time TaqMan-based PCR with the ABI Prism 7900HT (Life Technologies, Darmstadt, Germany). ANOVA and post hoc analysis according to Turkey were performed using SPSS 22 (IBM, Armonk, USA). For silico analysis, Diana tools were applied to determine target genes of miR-210 and related functions and pathways. All the statistical tests were two-sided, and the level of statistical significance was set at P < 0.05. The small nuclear U6 RNA was used as an endogenous control. Results: ANOVA revealed significant differences in expression levels of miR-210 according to the tumor progression. Interestingly, organ-confined PCa showed the lowest expression level of miR-210 in our analysis. No sig. differences in miR-210 expression between normal tissues, HGPIN and organ-confined PCa and between advanced PCa, metastatic diseases and CRPC were observed. However, miR-210 expression was significantly higher in metastatic diseases and CRPC in comparison to organ-confined PCa. The silico analysis showed that genes regulated by miR-210 were associated with homologous recombination, non-homologous end-joining, the cell cycle regulation and synthesis of DNA. Conclusions: We observed an enhanced overexpression of hypoxia-related miRNA-210 in primary tumor of metastatic prostate cancer and CRPC in comparison to organ-confined PCa.

miRNA expression profiles in high-grade prostatic intraepithelial neoplasia

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Background: High-grade prostatic intraepithelial neoplasia (HGPIN) is widely believed to be a precursor of prostate cancer (PCa). However, little is known about the expression of miRNAs variations in HGPIN compared to normal tissues and PCa. Methods: The expression data of 1054 miRNAs from TCGA were applied to identify relevant miRNAs associated with tumor progression (i.e., miR-98-5p, miR-183-5p, 345-5p, miR-143 miR-210-3p and miR-378-3p). miRNA were isolated by miRNeasy FFPE kit (Qiagen, Hilden, Germany) from paraffin-embedded tissues (FFPE) of prostate specimens with PCa, HGPIN and normal tissues. Early-stage PCa was defined as PCa with pT2 tumor stage, Gleason score <=7a (3+4) and PSA level <10 ng/ml. Quantitative miRNA expression data were acquired and analyzed using a real-time TaqMan-based PCR with the ABI Prism 7900HT (Life Technologies, Darmstadt, Germany). ANOVA analysis were performed to evaluate the expression of miRNAs between HGPIN, Normal and PCa tissues. All statistical analysis was performed using SPSS (IBM, Armonk, USA). P values were adjusted using the false discovery rate for multiple comparisons. The small nuclear U6 RNA was used as an endogenous control. Results: The expression of miR-143-3p, miR-210-3p and miR-345-5p and miR-98-5-p were varied between normal tissue, HGPIN and early-stage PCa. Interestingly, decrease in expression of miR-143.-3p, miR-98-5p and miR-210-3p was associated with tumor development (Normal tissues > HGPIN > early-stage PCa) (FDR<0.001). Furthermore, overexpression of miR-345-5p was observed in normal tissues compared to HGPIN and early-stage PCa, which both showed similar expression level of miR-345-5p. No significant differences in expression of miR-375, miR-183-5p and miR-378-3p were observed between HGPIN and PCa. These miRNAs were interacted with genes related to HIF-1 signaling pathway, p53 signaling pathway, androgen receptor signaling pathway, intrinsic apoptotic signaling pathway, RNA transcription, homologous recombination and non-homologous end-joining. Conclusions: HGPIN shows an altered expression of miRNAs interact with genes related to hypoxia, androgen receptor signaling pathway, cell cycle and epigenetic regulation.

Roles of thymidylate synthase and dihydropyrimidine dehydrogenase expression in blood as predictors of response to multimodal therapy in esophageal cancer

BACKGROUND

Thymidylate synthetase (TS) and dihydropyrimidine dehydrogenase (DPD) RNA expression in peripheral blood was examined as a noninvasive molecular predictor of response to neoadjuvant radiochemotherapy in patients with locally advanced cancer of the esophagus.

METHODS

Blood samples were drawn from 29 patients with esophageal cancer (10 squamous cell carcinomas and 19 adenocarciomas) before neoadjuvant radiochemotherapy. After extraction of cellular tumor RNA from blood samples, quantitative expression analysis of TS and DPD was performed with quantitative real-time reverse-transcription polymerase chain reaction.

RESULTS

Twenty of 29 (68%) of patients had a minor histopathologic response, and 9 of 29 (32%) had a major response to neadjuvant radiochemotherapy. RNA expression in the blood of patients was detectable for TS in 86%, for DPD in 97%, and in 100% for β-actin. No significant associations were detected between TS and DPD expression levels and clinical variables of the patients. A high expression level for TS was associated with a minor response to neoadjuvant treatment (P = .046), while there was no significant association between DPD and response to therapy. Combined analysis of TS and DPD expression increased the specificity for the prediction of response to 100%. No major responder to therapy had high expression levels for both genes in their peripheral blood.

CONCLUSION

Quantitation of TS and DPD in peripheral blood may be a highly specific analysis to identify a subset of patients who do not respond to neoadjuvant radiochemotherapy and may therefore prevent expensive, noneffective, and potentially harmful therapies in a substantial number of patients with esophageal cancer.

The role of the homeobox genes BFT and CDX2 in the pathogenesis of non-small cell lung cancer

BACKGROUND

The role of the homeobox genes Backfoot (BFT) and caudal-related Homeobox 2 (CDX2) in the pathogenesis of non-small cell lung cancer (NSCLC) is unclear. The goal of this study was to investigate the mRNA expression of BFT and CDX2 in NSCLC and to determine the association with the pathogenesis and the potential as a biomarker of this disease.

MATERIALS AND METHODS

The mRNA expression of BFT and CDX2 was analyzed by quantitative real-time RT-PCR in the tumor and matching normal tissue from 23 patients with NSCLC.

RESULTS

The mRNA expression was detectable with the following frequencies in the tumor (t) and normal (n) tissues: BFT=100% (n), 100% (t); CDX2=100% (n), 100% (t). The median CDX2 mRNA expression was 0.85 (range: 0.01-15.47) in the tumor tissue and 0.045 (range: 0-1.36) in the matching normal lung tissue (p=0.001). The median BFT mRNA expression was 0.0034 (range: 0-0.35) in the tumor tissue and 0.0001 (range: 0-0.10) in the matching normal lung tissue (p=n.s.). There were no associations between the mRNA expression levels of BFT and CDX2 and clinicopathological variables.

CONCLUSION

The mRNA expression of the homeobox genes is detectable at a high frequency in the tumor and normal tissue of patients with non-small cell lung cancer. Up-regulation of CDX2 mRNA expression appears to be associated with the pathogenesis of this malignant disease. The quantification of CDX2 and BFT mRNA expression in lung tissue is a potential biomarker for the identification of patients at risk of the development of NSCLC.

Death-associated protein kinase (DAPK) promoter methylation and response to neoadjuvant radiochemotherapy in esophageal cancer

BACKGROUND

Multiple studies have shown that promoter methylation of tumor suppressor genes underlies esophageal carcinogenesis. Hypothetically, methylation resulting in tumor suppressor gene inactivation might result in tumors that are unresponsive to chemotherapy and radiation. Accordingly, our aim was to investigate if aberrant methylation of the apoptosis-related gene Death-Associated Protein Kinase (DAPK) could be used as a predictor of response to neoadjuvant therapy in locally advanced cancer of the esophagus.

METHODS

Tumor and normal esophageal tissues were obtained from 50 patients with locally advanced cancer of the esophagus prior to neoadjuvant radiochemotherapy. DAPK methylation analysis was performed on all samples by methylation-specific real-time polymerase chain reaction (PCR).

RESULTS

Seventeen (34%) patients showed a major and 33 (66%) a minor histomorphological response to neoadjuvant therapy. DAPK methylation was detectable in normal esophageal tissues with a frequency of 10% and in tumor tissue with a frequency of 78%. The median methylation level for DAPK was 2.7 x 10(-3) in tumor compared with 0.1 x 10(-3) in normal tissues (p < 0.001). DAPK methylation was not associated with response to neoadjuvant therapy or prognosis after esophagectomy.

CONCLUSION

Aberrant DAPK methylation in tumor tissues is significantly higher compared with matching normal esophageal tissues, suggesting a fundamental role of this epigenetic alteration in the pathogenesis of this disease. The level of DAPK methylation in pretreatment biopsies of patients with locally advanced cancer of the esophagus is no marker for the prediction of histomorphological regression or prognosis following neoadjuvant chemoradiation in this disease.

Association of COX-2 expression with corresponding active and chronic inflammatory reactions in Barrett's metaplasia and progression to cancer

AIMS

Risk reduction for Barrett's cancer in individuals taking non-steroidal anti-inflammatory drugs has been reported. Cyclooxygenase (COX)-2, one of the inhibited enzymes, is putatively involved in Barrett's cancer pathogenesis. The aim of this study was to examine a possible association between COX-2 protein expression and the development and progression of the Barrett's metaplasia-dysplasia-carcinoma sequence and the type and degree of associated inflammatory reaction.

METHODS AND RESULTS

Squamous epithelium, metaplastic, low-grade, high-grade dysplastic lesions and tumour tissue of 49 resection specimens from patients with Barrett's adenocarcinoma were immunohistochemically analysed. Active and chronic inflammatory reactions were classified according to the Updated Sydney System. Within the Barrett's sequence, a significant progressive increase in COX-2 expression was identified (P < 0.0001). The most significant differences were detected between squamous epithelium and Barrett's metaplasia (P < 0.001) and from low- to high-grade dysplasia (P < 0.0001). Active and chronic inflammation were significantly different between squamous epithelium and Barrett's metaplasia (P < 0.0001), but not during further progression in the sequence.

CONCLUSIONS

Increasing COX-2 expression in Barrett's metaplasia is significantly associated with a change in the local inflammatory reaction, but not during further progression through dysplasia to cancer. This supports the potential of a chemoprevention strategy using COX-2 inhibitors independent of the extent and type of the inflammatory reaction in Barrett's oesophagus.

COX-2 mRNA expression is significantly increased in acid-exposed compared to nonexposed squamous epithelium in gastroesophageal reflux disease

BACKGROUND

Little is known about the role of cyclooxygenase (COX)-2 in gastroesophageal reflux disease (GERD) and the development of Barrett's metaplasia. The objectives of this study were to further analyze COX-2 mRNA expression in patients with GERD compared to Barrett's esophagus (BE) and Barrett's cancer (BC).

METHODS

Tissue samples from 110 patients with GERD (n = 43), BE (n = 20), and BC (n = 47) were obtained in routine upper GI endoscopy. Expression levels of COX-2 were measured by quantitative real-time reverse trancriptase polymerase chain reaction (RT-PCR). Also, 24-h pH monitoring was performed in all patients of the GERD study group and the DeMeester composite score was used to match COX-2 mRNA expression with the severity of acid exposure in the lower esophagus.

RESULTS

COX-2 mRNA is progressively upregulated within the metaplasia-dysplasia-adenocarcinoma (MDA) sequence (p = 0.001). COX-2 levels of the squamous epithelium in the distal esophagus from patients with GERD and a pathologic mean DeMeester score (>14.72) were significantly higher than in patients with normal DeMeester scores (p = 0.01).

CONCLUSION

In summary our findings suggest that alterations in COX-2 mRNA expression occur independently of endoscopic or histologic signs of GERD in the acid-exposed squamous epithelium of the distal esophagus. However, this early COX-2 increase in GERD is further upregulated within the MDA sequence for yet unknown reasons.

HIF-1alpha mRNA is not associated with histopathological regression following neoadjuvant chemoradiation in esophageal cancer

BACKGROUND

Hypoxia-inducible factor-1alpha (HIF-1alpha) expression was reported to be associated with tumor growth, progression and resistance to radio-/chemotherapy. Whether HIF-1alpha mRNA or protein expression is associated with histomorphological response or prognosis following neoadjuvant chemoradiation and surgery in resectable, locally-advanced esophageal cancer was analyzed.

PATIENTS AND METHODS

Fifty-three patients received neoadjuvant chemoradiation (cisplatin, 5-fluorouracil, 36 Gy) followed by transthoracic en bloc esophagectomy. HIF-1alpha mRNA and protein expressions were analyzed by quantitative RT-PCR and immunostaining.

RESULTS

In squamous cell carcinoma, HIF-1alpha mRNA expression was significantly higher than in paired normal epithelium (p < 0.001). Normal squamous epithelium showed significant elevated expression in adenocarcinomas, suggesting a field effect (p < 0.04). HIF-1alpha protein expression showed a significant regulation following chemoradiation. Neither HIF-1alpha mRNA nor protein expression was associated with histomorphological regression or prognosis.

CONCLUSION

HIF-1alpha mRNA expression is differentially upregulated in esophageal squamous cell carcinoma compared to adenocarcinomas, but does not predict tumor regression or prognosis.

High cyclooxygenase-2 expression following neoadjuvant radiochemotherapy is associated with minor histopathologic response and poor prognosis in esophageal cancer

PURPOSE

High expression of cyclooxygenase-2 (COX-2) was shown to inhibit chemotherapy- and radiotherapy-induced apoptosis. We analyzed the association of COX-2 mRNA and protein expression with histomorphologic response to neoadjuvant radiochemotherapy in esophageal cancer.

EXPERIMENTAL DESIGN

Fifty-two patients with resectable esophageal cancers (cT2-4, Nx, and M0) received neoadjuvant radiochemotherapy (cisplatin, 5-5-fluorouracil, 36 Gy) followed by transthoracic en bloc esophagectomy. Histomorphologic regression was defined as major response when resected specimens contained less than 10% of residual vital tumor cells. RNA was isolated from endoscopic biopsies (paired tumor and normal tissue) before neoadjuvant treatment and quantitative real-time reverse transcriptase-PCR (Taqman) assays were done to determine COX-2 mRNA expression levels standardized for beta-actin. COX-2 protein expression in pretreatment biopsies and post-therapeutic resection specimens was analyzed by immunostaining of tumor cells.

RESULTS

Median COX-2 mRNA expression levels were significantly (P < 0.0001) different between paired tumor (median, 2.2) and normal tissues (median, 0.159). Comparison of pre-therapeutic and posttherapeutic specimens showed a significant difference (P < 0.006) in COX-2 protein expression. Twelve of 52 tumors showed down-regulation and 3 of 52 showed up-regulation of COX-2 protein expression during neoadjuvant radiochemotherapy. High COX-2 protein expression in post-therapeutic resection specimens was significantly associated with minor histopathologic response (P < 0.04) and poor prognosis (5-year survival probabilities: 26.3 +/- 8.2% for minor and 58.6% +/- 12.9% for major histopathologic response; P < 0.01).

CONCLUSION

High COX-2 protein expression following neoadjuvant radiochemotherapy in resection specimens is significantly associated with minor histopathologic response to neoadjuvant therapy and very poor prognosis.

Survivin mRNA in peripheral blood is frequently detected and significantly decreased following resection of gastrointestinal cancers

BACKGROUND AND OBJECTIVES

We evaluated if mRNA expression of survivin, an inhibitor of apoptosis, can be used to detect circulating tumor cells in peripheral blood of patients with various gastrointestinal cancers and if they decrease following complete surgical resection.

METHODS

Blood samples from 40 gastrointestinal cancer patients were analyzed prior and following surgical resection by direct quantitative real-time reverse transcriptase-PCR (RT-PCR) assays.

RESULTS

Survivin mRNA expression was pre-operatively detected in 35 of 40 cancer patients (88%). Post-operative survivin levels were significantly lower than pre-operative levels in 59% of resected patients and were non-detectable in 38% (Wilcoxon rank test: P < 0.04).

CONCLUSIONS

This is the first report showing that direct quantitative real-time RT-PCR analysis of survivin mRNA expression in peripheral blood of patients with gastrointestinal cancers is technically feasible. Survivin mRNA levels fall significantly following complete resection and might become a molecular marker for the completeness of surgical resection.

High specificity of quantitative excision repair cross-complementing 1 messenger RNA expression for prediction of minor histopathological response to neoadjuvant radiochemotherapy in esophageal cancer

PURPOSE

The excision repair cross-complementing 1 (ERCC1) gene is coding for a nucleotide excision repair protein involved in the repair of radiation- and chemotherapy-induced DNA damage. We examined the potential of quantitative ERCC1 mRNA expression to predict minor or major histopathological response to neoadjuvant radiochemotherapy (cisplatin, 5-fluorouracil, and 36 Gy of radiation) followed by transthoracic en bloc esophagectomy in patients with locally advanced esophageal cancer (cT(2-4), N(x), M(0)).

EXPERIMENTAL DESIGN

Tissue samples were collected by endoscopic biopsy before treatment. RNA was isolated from biopsies, and quantitative real-time reverse transcriptase PCR assays were performed to determine ERCC1 mRNA expression. Relative mRNA levels (tumor/normal ratios) were calculated as (ERCC1/beta-actin in tumor)/(ERCC1/beta-actin in paired normal tissue). ERCC1 expression levels were correlated with the objective histopathological response in resected specimens. Histomorphological regression was defined as major response when resected specimens contained <10% of residual vital tumor cells or in case a pathologically complete response was achieved.

RESULTS

Twelve of 36 tumors showed a major histopathological response, and 24 of 36 showed a minor histopathological response. Relative expression levels of ERCC1 of >1.09 were not associated with a major histopathological response (sensitivity, 62.5%; specificity, 100%) and 15 of 24 patients with minor histopathological response to the delivered neoadjuvant radiochemotherapy could be unequivocally identified. This association of dichotomized relative ERCC1 mRNA expression and histopathological response was statistically significant (P < 0.001).

CONCLUSIONS

Relative expression levels of ERCC1 mRNA determined by quantitative real-time reverse transcriptase-PCR appear highly specific to predict minor response to our neoadjuvant radiochemotherapy protocol in patients with locally advanced esophageal cancer and could be applied to prevent expensive, noneffective, and potentially harmful therapies in a substantial number (42%) of patients.