Molecular cytogenetic characterization of esophageal cancer detected by comparative genomic hybridization

Expression of SEC62 Oncogene in Benign, Malignant and Borderline Melanocytic Tumors-Unmasking the Wolf in Sheep's Clothing?

Simple Summary

Amplification and overexpression of the SEC62 oncogene was reported in a variety of human cancers and was associated with poor prognosis as well as lymph node and distant metastases. In this study, SEC62 expression was analyzed in benign, borderline, and malignant melanocytic lesions of 209 patients. We found the highest expression in Spitz nevi, followed by melanoma metastases, primary melanoma, congenital nevi, and blue nevi. In melanoma patients, high Sec62 levels correlated with shorter overall and progression-free survival. Significantly higher Sec62 levels were found in melanomas with lymph node and distant metastases compared with those without. Taken together, these data suggest a relevant role of SEC62 as a metastasis-stimulating oncogene in melanoma development, which represents a promising therapeutic target.

Abstract

SEC62 oncogene located at chromosomal region 3q26 encodes for a transmembrane protein of the endoplasmic reticulum (ER) and is expressed at high levels in numerous human malignancies. SEC62 overexpression has been associated with worse prognosis and high risk for lymphatic and distant metastases in head and neck cancer, cervical cancer, hepatocellular cancer, and lung cancer. However, its role in the development and tumor biology of melanocytic lesions has not been investigated so far. An immunohistochemical study including 209 patients with melanocytic lesions (malignant melanoma (MM), n = 93; melanoma metastases (MET), n = 28; Spitz nevi (SN), n = 29; blue nevi (BN), n = 21; congenital nevi (CN), n = 38) was conducted and SEC62 expression was correlated with clinical data including patient survival and histopathological characteristics. SN showed the highest SEC62 expression levels followed by MET, MM, CN, and BN. High SEC62 expression correlated with a shorter overall and progression-free survival in MM patients. Additionally, high Sec62 levels correlated significantly with higher tumor size (T stage), the presence of tumor ulceration, and the presence of lymph node as well as distant metastases. Strikingly, SEC62 expression showed a strong correlation with Clark level. Taken together, these data demonstrate that SEC62 is a promising prognostic marker in MM and has the potential to predict biological behavior and clinical aggressiveness of melanocytic lesions.

Sec62/Ki67 and p16/Ki67 dual-staining immunocytochemistry in vulvar cytology for the identification of vulvar intraepithelial neoplasia and vulvar cancer: a pilot study

PURPOSE

The aim of this study was to analyze the diagnostic performance of a newly established immunocytochemical dual-staining protocol for the simultaneous expression of SEC62 and Ki67 in vulvar liquid-based cytology specimens for the identification of vulvar intraepithelial neoplasia (VIN) and vulvar cancer. In addition, we investigated the p16/Ki67 dual stain, which has already been established in cervical cytology.

MATERIALS AND METHODS

For this pilot study, residual material from liquid-based cytology was collected retrospectively from 45 women. The presence of one or more double-immunoreactive cells was considered as a positive test result for Sec62/Ki67 and p16/Ki67 dual staining. The test results were correlated with the course of histology.

RESULTS

All cases of VIN and vulvar cancer were Sec62/Ki67 and p16/Ki67 dual-stain positive, and normal and low-grade squamous intraepithelial lesions were all negative. The sensitivity of cytology for VIN + cases was 100% (22/22), whereas punch biopsy classified one case of vulvar carcinoma as inflammation. All cases with high-intensity (grades 3 and 4) Sec62 staining in Sec62/Ki67-positive cases were carcinomas.

CONCLUSIONS

The results of this study demonstrate that Sec62/Ki67 and p16 Ki67 dual-staining cytology could be a promising adjunctive diagnostic tool for VIN and squamous cell carcinoma, in addition to standard histology.

Sec62/Ki67 dual staining in cervical cytology specimens: a new marker for high-grade dysplasia

PURPOSE

In the previous studies, we demonstrated that Sec62 is essential for tumor cell migration, epithelial-to-mesenchymal transition, and intracellular stress tolerance. An increase in Sec62 expression correlated with an increase in cervical dysplasia severity in liquid-based cytology specimens. Ki67 is an established proliferation marker. Thus, in this study, we examined a method of Sec62/Ki67 dual staining for the detection of high-grade dysplasia and cancer in cervical liquid-based cytology specimens.

METHODS

Sec62/Ki67 dual staining was performed on 100 cervical liquid-based cytology specimens. The staining results were correlated with cytological, immunocytological (p16/Ki67), colposcopic, and histological findings.

RESULTS

All 56 (n = 56, 100%) cases of cervical intraepithelial neoplasia grade 3 and cervical cancer (CIN3+ lesions) were positive for Sec62/Ki67 staining, while low-grade lesions and normal cells were negative. Sec62/Ki67 staining was highly sensitive and specific for the detection of CIN2+ and CIN3+ lesions (94.37%; 100% and 100%; 84.09%, respectively).

CONCLUSIONS

Sec62/Ki67 dual-staining immunocytochemistry is a promising cytological tool for interpreting high-grade squamous lesions in cytological specimens and for assessing the risk of progression to cancer.

Expression of 3q oncogene SEC62 in atypical fibroxanthoma-immunohistochemical analysis of 41 cases and correlation with clinical, viral and histopathologic features

Atypical fibroxanthoma (AFX) is a rare mesenchymal tumor with predominance in older male patients located mainly in chronically UV-exposed skin. Differentiation from clinically more aggressive pleomorphic dermal sarcoma (PDS) is still under debate and immunohistochemical markers are not available yet. An immunohistochemical study, including 41 cases of AFX was conducted to investigate the expression of 3q encoded oncogene SEC62 in AFX and determine the associations with histomorphologic, clinical and viral parameters. Our cohort displayed a mean of 79.9 years at the onset of the disease. In total, 90.2% (37/41) AFXs were located in the head and neck area, whereas, four were located at the extremities (9.7%). Tumor diameter ranged between 0.06 and 40 cm² with a mean of 5.7 cm². SEC62 expression was markedly increased in lesional tissue compared with the adjacent healthy squamous epithelium. We found significantly higher expression of SEC62 in cases of AFX with tumor necrosis. Tendency of higher Sec62-IRS-scores were found for tumors with higher Clark levels and a tumor size >5 cm². Sec62 is involved in endoplasmic reticulum stress tolerance and cell migration, and has been identified as a novel prognostic marker for non-small cell lung cancer as well as head and neck squamous cell carcinoma. For the first time, to the best of our knowledge, we suggest a role of 3q oncogene SEC62 in AFX and discuss a potential prognostic relevance in cases of disputable AFX with unfavorable histomorphologic features and may initiate a discussion on Sec62 serving as discriminating marker between AFX and PDS.

Let's talk about Secs: Sec61, Sec62 and Sec63 in signal transduction, oncology and personalized medicine

The heterotrimeric Sec61 complex and the dimeric Sec62/Sec63 complex are located in the membrane of the human endoplasmic reticulum (ER) and play a central role in translocation of nascent and newly synthesized precursor polypeptides into the ER. This process involves targeting of the precursors to the membrane and opening of the polypeptide conducting Sec61 channel for translocation. Apart from this central role in the intracellular transport of polypeptides, several studies of the last decade uncovered additional functions of Sec proteins in intracellular signaling: Sec62 can induce ER-phagy in the process of recovery of cells from ER stress and the Sec61 channel can also act as a passive ER calcium leak channel. Furthermore, mutations, amplifications and an overexpression of the SEC genes were linked to various diseases including kidney and liver diseases, diabetes and human cancer. Studies of the last decade could not only elucidate the functional role of Sec proteins in the pathogenesis of these diseases, but also demonstrate a relevance of Sec62 as a prognostic and predictive biomarker in head and neck cancer, prostate and lung cancer including a basis for new therapeutic strategies. In this article, we review the current understanding of protein transport across the ER membrane as central function of Sec proteins and further focus on recent studies that gave first insights into the functional role and therapeutic relevance of Sec61, Sec62 and Sec63 in human diseases.

Identification of SEC62 as a potential marker for 3q amplification and cellular migration in dysplastic cervical lesions

Background

Chromosome 3 amplification affecting the 3q26 region is a common genomic alteration in cervical cancer, typically marking the transition of precancerous intraepithelial lesions to an invasive phenotype. Though potential 3q encoded target genes of this amplification have been identified, a functional correlation of potential oncogenic function is still missing. In this study, we investigated copy number changes and the expression level of SEC62 encoded at 3q26.2 as a new potential 3q oncogene in dysplastic cervical lesions and analyzed its role in cervical cancer cell biology.

Methods

Expression levels of Sec62 and vimentin were analyzed in liquid based cytology specimens from 107 women with varying grades of cervical dysplasia ranging from normal cases to cancer by immunofluorescence cytology. Additionally, a subset of 20 representative cases was used for FISH analyses targeting SEC62. To further explore the functional role of Sec62 in cervical cancer, HeLa cells were transfected with a SEC62 plasmid or SEC62 siRNA and analyzed for their proliferation and migration potential using real-time monitoring and trans-well systems as well as changes in the expression of EMT markers.

Results

FISH analyses of the swabbed cells showed a rising number of SEC62 gains and amplifications correlating to the grade of dysplasia with the highest incidence in high grade squamous intraepithelial lesions and squamous cell carcinomas. When analyzing the expression level of Sec62 and vimentin, we found a gradually increasing expression level of both proteins according to the severity of the dysplasia. In functional analyses, SEC62 silencing inhibited and SEC62 overexpression stimulated the migration of HeLa cells with only marginal effects on cell proliferation, the expression level of EMT markers and the cytoskeleton structure.

Conclusions

Our study suggests SEC62 as a target gene of 3q26 amplification and a stimulator of cellular migration in dysplastic cervical lesions. Hence, SEC62 could serve as a potential marker for 3q amplification, providing useful information about the dignity and biology of dysplastic cervical lesions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2739-6) contains supplementary material, which is available to authorized users.

MicroRNA-143 functions as a tumor suppressor in human esophageal squamous cell carcinoma

Esophageal cancer is one of the most common cancers worldwide with a poor prognosis. MicroRNAs(miRNAs) are a class of naturally occurring small noncoding RNAs and play an important role in cancer initiation and development. In this study, we demonstrate that the expression levels of miR-143 and miR-145 were significantly decreased in ESCC tissues in comparison with adjacent normal esophageal squamous tissues(NESTs). Furthermore, an inverse correlation between miR-143 and tumor invasion depth and lymph node metastasis was observed. The enforced expression of miR-143 induced growth suppression and apoptosis of ESCC cells. Rescue of miR-143 significantly suppressed the ESCC cells migration and invasion capabilities. Moreover, we show that functions of miR-143 in ESCC are mediated at least in part by the inhibition of extracellular signal regulated kinase-5(ERK-5) activity. These results prove that miR-143 may act as a tumor suppressor in ESCC.

Frequent silencing of protocadherin 8 by promoter methylation, a candidate tumor suppressor for human gastric cancer

The cadherins are a family of cell surface glycoproteins responsible for cell adhesion which play an important role in cell morphology, contact inhibition and signal transduction during tumorigenesis. Protocadherin 8 (PCDH8), a member of the cadherin family, has been reported to act as a tumor suppressor involved in oncogenesis in breast cancer. In this study, we aimed to investigate the epigenetic inactivation of PCDH8 and its tumor suppressor function in gastric cancer. The expression of PCDH8 was markedly reduced or silenced in gastric cancer cell lines compared with normal gastric cells or tissues. Methylation of the PCDH8 gene promoter was observed in 100% (4/4) of cell lines and 55.38% (36/65) of the primary gastric cancer by methylation-specific PCR, but not in normal gastric mucosa (0/10). Methylated PCDH8 was significantly associated with lymph node metastasis in a logistic regression analysis. The demethylation reagent 5-aza-2'-deoxycytidine was able to restore or upregulate PCDH8 expression in gastric cancer cell lines. Ectopic expression of PCDH8 in silenced gastric cancer cells significantly inhibited cell migration and induced apoptosis. For the first time, our study demonstrates the epigenetic inactivation of PCDH8 by promoter methylation and its tumor suppressor function in human gastric cancer. Thus, PCDH8 could be identified as a candidate tumor suppressor in human gastric cancer.

[Chromosomal and genomic aberrations in esophageal squamous cell carcinoma]

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies with poor prognosis in China. Patients with ESCC may present with vague symptoms in early stage and most of the cases are diagnosed at advanced stage, without the chance of optimal therapy. In the development and progression of ESCC, cytogenetic and molecular aberrations are frequently observed. This review is to summarize the advances in the chromosomal and genomic alterations of ESCC reported recently.

The cluster of miR-143 and miR-145 affects the risk for esophageal squamous cell carcinoma through co-regulating fascin homolog 1

MicroRNAs (miRNAs), 18–24 nt non-coding RNAs, are thought to play important roles in cell proliferation, differentiation, apoptosis, and development. Recent studies suggest that some of the known microRNAs map to a single genomic locale within a single polycistronic transcript. But the roles of the cluster remain to be known. In order to understand the role and mechanism of a cluster of miR-143 and miR-145 in esophageal squamous cell carcinoma (ESCC), the association of mature miR-143 and miR-145 expression with the risk for esophageal cancer was evaluated in ESCC patients with a case-control study, and target protein regulated by mature miRNA was analyzed in ESCC cell lines with 3′UTR luciferase reporter assay. The expression levels of miR-143 and miR-145 were determined in 110 pairs of esophageal cancer tissues and adjacent normal tissues using real-time reverse transcription PCR. The relative expression of miR-143 and miR-145 were statistically different between cancer tissues and matched controls. The combined expression of miR-143 and miR-145 was significantly associated with the risk for esophageal cancer. Meanwhile, the reduced expression of two miRNAs in tumor patient was supposed to have a trend of lymph node metastases. The co-expression pattern of miR-143 and miR-145 was analyzed with Pearson correlation. It showed a significant correlation between these two miRNAs expression both in tissues and tumor cell lines. 3′UTR luciferase reporter assay indicated that Fascin Homolog 1 (FSCN1) could be co-regulated by miR-143 and miR-145. The protein level of FSCN1 showed no significant linear correlation with miR-143 and miR-145 expression in ESCC cell lines with Western blotting analysis. In conclusion, since miR-143 and miR-145 could regulate oncogenic FSCN1 and take part in the modulation of metastases, the result suggested the combination variable of miR-143 and miR-145 as a potential biomarker for earlier diagnosis and prognosis of esophageal cancer.

Sec62 bridges the gap from 3q amplification to molecular cell biology in non-small cell lung cancer

The molecular carcinogenesis of lung cancer has yet to be clearly elucidated. We investigated the possible oncogenic function of SEC62 in lung cancer, which was predicted based on our previous findings that lung and thyroid cancer tissue samples exhibited increased Sec62 protein levels. The SEC62 gene locus is at 3q26.2, and 3q amplification is reportedly the most common genomic alteration in non-small cell lung cancer. We analyzed SEC62 mRNA and protein levels in tissue samples from lung cancer patients by real-time quantitative PCR, Western blot, and IHC and found significantly increased SEC62 mRNA and protein levels in tumors compared with tumor-free tissue samples from the same patients. Correlation analyses revealed significantly higher Sec62 levels in tumors with lymph node metastases compared with nonmetastatic tumors, as well as in poorly compared with moderately differentiated tumors. On the basis of these promising results, we examined the role of Sec62 in cancer cell biology in vitro. Cell migration assays with lung and thyroid cancer cells showed distinct stimulation of migration in SEC62-overexpressing cells and inhibition of migration in Sec62-depleted cells. Moreover, we found that SEC62 silencing sensitized the cells to thapsigargin-induced endoplasmic reticulum stress. Thus, our results indicate that SEC62 represents a potential candidate oncogene in the amplified 3q region in cases of non-small cell lung cancer and harbors various functions in cancer cell biology.

A new frontier in personalized cancer therapy: mapping molecular changes

Mutations in the genome of a normal cell can affect the function of its many genes and pathways. These alterations could eventually transform the cell from a normal to a malignant state by allowing an uncontrolled proliferation of the cell and formation of a cancer tumor. Each tumor in an individual patient can have hundreds of mutated genes and perturbed pathways. Cancers clinically presenting as the same type or subtype could potentially be very different at the molecular level and thus behave differently in response to therapy. The challenge is to distinguish the key mutations driving the cancer from the background of mutational noise and find ways to effectively target them. The promise is that such a molecular approach to classifying cancer will lead to better diagnostic, prognostic and personalized treatment strategies. This article provides an overview of advances in the molecular characterization of cancers and their applications in therapy.

Silence of HIN-1 expression through methylation of its gene promoter in gastric cancer

AIM: To clarify the role of high in normal-1 (HIN-1) gene promoter methylation during gastric cancer development.

METHODS: Gastric cancer cell lines and tissue specimens were analyzed for expression of HIN-1 mRNA and protein using the semi-quantitative reverse transcription polymerase chain reaction and immunohistochemistry. The methylation of the HIN-1 gene promoter was detected in gastric carcinoma cells and tissues using methylation-specific polymerase chain reaction. The 3-(4,5-dimethylthiazol-2yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium cell viability assay and flow cytometry were used to assess the changes in behaviors of gastric cancer cells with or without 5-aza-2’-deoxycytidine treatment.

RESULTS: HIN-1 was not expressed in 4 of 5 gastric cancer cell lines. The demethylation reagent 5-aza-2’-deoxycytidine was able to induce or upregulate HIN-1 expression in gastric cancer cell lines, which is associated with reduction of tumor cell viability. Furthermore, methylation of the HIN-1 gene promoter was shown in 57.8% (26/45) of the primary gastric cancer and 42.1% (17/38) of adjacent tissue samples, but was not shown in normal gastric mucosa (0/10). From the clinicopathological data of the patients, methylation of the HIN-1 gene promoter was found to be associated with tumor differentiation (P = 0.000).

CONCLUSION: High methylation of HIN-1 gene promoter results in silence of HIN-1 expression in gastric cancer. 5-aza-2’-deoxycytidine reverses HIN-1 methylation and reduces viability of gastric cancer cells.