Cu-Tai Lu

JK1 (FAM134B) gene and colorectal cancer: A pilot study on the gene copy number alterations and correlations with clinicopathological parameters

AIMS The aims of the study are to characterize changes in JK-1 (FAM134B) at the DNA level in colorectal adenocarcinoma and adenoma and exploring the possible correlations with clinical and pathological features. METHOD JK-1 gene DNA copy number changes were studied in 211 colorectal carcinomas, 32 colorectal adenoma and 20 colorectal non-cancer colorectal tissue samples by real-time quantitative polymerase chain reaction. The results were correlated with clinical and pathological parameters. RESULTS Colorectal adenomas were more likely to be amplified than deleted with regard to JK-1 (FAM134B) DNA copy number change. The copy number level of JK-1 (FAM134B) DNA in colorectal adenocarcinomas was significantly lower in comparison to colorectal adenomas. Changes in JK-1 (FAM134B) DNA copy number were associated with histological subtypes, and cancer stage. Lower copy numbers were associated with higher tumor stage, lymph node stage and overall pathological stage of cancer. Conversely, higher DNA copy numbers were detected more often in the mucinous adenocarcinoma. CONCLUSIONS This is the first study showing significant correlations of the JK-1 (FAM134B) gene copy number alterations with clinical and pathological features in a large cohort of pre-invasive and invasive colorectal malignancies. The changes in DNA copy number associated with progression of colorectal malignancies reflect that JK-1 (FAM134B) gene could play a role in controlling some steps in development of the invasive phenotypes.

The roles of JK-1 (FAM134B) expressions in colorectal cancer.

The aims of the present study are to investigate the clinicopathological correlations of JK-1(FAM134B) expression and its relationship to carcinogenesis in a colorectal adenoma-adenocarcinoma model. JK-1(FAM134B) protein expression was studied in a colon cancer cell line by Western blot and immunocytochemistry. JK-1(FAM134B) expression profiles at mRNA and protein levels were investigated in cancer tissues from 236 patients with colorectal adenocarcinoma and 32 patients with colorectal adenoma using real-time polymerase chain reaction and immunohistochemistry. The findings were then correlated with the clinicopathological features of these tumours. JK-1(FAM134B) protein was demonstrated in the colon cancer cells by Western blot. The protein was located in the nuclei of the tumour cells at both cellular and tissue levels. In colorectal adenocarcinomas, lower levels of JK-1(FAM134B) protein expression were associated with younger age (p=0.032), larger tumour size (p=0.004), advanced cancer stages (p=0.016) and higher rates of cancer recurrence (p=0.04). Also, lower levels of JK-1(FAM134B) mRNA expression were associated with advanced cancer stages (p=0.02) and presence of lymphovascular invasion (p=0.014). Higher JK-1(FAM134B) mRNA and protein expression levels were identified in adenomas and non-neoplastic mucosae, compared to carcinomas (p=0.005). To conclude, JK-1(FAM134B) mRNA expression and JK1 (FAM134B) protein levels varied with the different stages of progression of colorectal tumours. The expression levels of the gene were associated with clinicopathological features in patients with colorectal adenocarcinoma suggesting that JK-1(FAM134B) gene has roles in controlling some steps in the development of the invasive phenotypes from colorectal adenoma to early staged as well as advanced staged colorectal adenocarcinomas.

MicroRNA-186-5p overexpression modulates colon cancer growth by repressing the expression of the FAM134B tumour inhibitor

Objectives: The role and underlying mechanism of miR‐186‐5p in colorectal cancer remain unknown. The present study aims to examine the various cellular effects of miR‐186‐5p in the carcinogenesis of colorectal cancer. Also, the interacting targets and association of clinicopathological factors with miR‐186‐5p expression in patients with colorectal cancer were analysed. Methods: The miR‐186‐5p expression levels in colorectal cancer tissues (n=126) and colon cancer cell lines (n=3) were analysed by real‐time PCR. Matched non‐neoplastic colorectal tissues and a non‐neoplastic colonic epithelial cell line were used as controls. Various in vitro assays such as cell proliferation, wound healing and colony formation assays were performed to examine the miR‐186‐5p specific cellular effects. Western blots and immunohistochemistry analysis were performed to examine the modulation of FAM134B, PARP9 and KLF7 proteins expression. Results: Significant high expression of miR‐186‐5p was noted in cancer tissues (p< 0.001) and cell lines (p<0.05) when compared to control tissues and cells. The majority of the patients with colorectal cancer (88/126) had shown overexpression of miR‐186‐5p. This miR‐186‐5p overexpression was predominantly noted with in cancer with distant metastasis (p=0.001), lymphovascular permeation (p=0.037), microsatellite instability (MSI) stable (p=0.015), in distal colorectum (p=0.043) and with associated adenomas (p=0.047). Overexpression of miR‐186‐5p resulted in increased cell proliferation, colony formation, wound healing capacities and induced alteration of cell cycle kinetics in colon cancer cells. On the other hand, inhibition of endogenous miR‐186‐5p reduced the cancer growth properties. miR‐186‐5p overexpression reduced FAM134B expression significantly in the cancer cells (p<0.01). Also, FAM134B and miR‐186‐5p expressions are inversely correlated in colorectal cancer tissues and cells. Conclusion: The miR‐186‐5p expression promotes colorectal cancer pathogenesis by regulating tumour suppressor FAM134B. Reduced cancer cells growth followed by inhibition of miR‐186‐5p highlights the potential of miR‐186‐5p inhibitor as a novel strategy for targeting colorectal cancer initiation and progression. HighlightsSignificant high expression of miR‐186‐5p was noted in cancer tissues and cells.miR‐186‐5p overexpression was correlated with adverse clinical factors of cancer.Modulation of miR‐186‐5p, regulate cancer cells growth and cell cycle kinetics.miR‐186‐5p overexpression reduced FAM134B expression in colorectal cancer.Anti‐miR‐186‐5p treatment inhibited colon cancer cells growth remarkably.

Gene amplified in oesophageal cancer 1 (GAEC1) amplification in colorectal cancers and its impact on patient's survival

GAEC1 (gene amplified in oesophageal cancer 1) is located at 7q22.1, first identified in oesophageal cancer.1 Initial work indicated that GAEC1 can act as an oncogene.2 Our pilot study found ∼80% of colorectal cancers showing amplification of GAEC1.3 In this research, we will study GAEC1 copy number in colon cancer cell lines and colorectal tissues, and its prognostic significance. Two human colon cancer cell lines (SW480 and SW48) and one normal colonic epithelial cell line (FHC) were obtained from American Type Culture Collection. Culturing conditions for these cell lines were as published previously.4 Tissues were collected from 283 patients (213 Australian; 70 Japanese) diagnosed with colorectal cancers. Ninety surgically removed non-cancer colorectal tissues (diverticular diseases, hyperplastic polyps and volvulus) were used as controls. H&E stained sections from each cancer were checked to select a block with sufficient cancer tissue and representative morphological features for each patient for DNA extraction...

Promoter hypermethylation inactivate tumour suppressor FAM134B and is associated with poor prognosis in colorectal cancer

The present study aims to examine promoter methylation status of FAM134B in a large cohort of patients with colorectal adenocarcinomas. The clinical significances and correlations of FAM134B promoter methylation with its expression are also analysed. Methylation‐specific high‐resolution melt‐curve analysis followed by sequencing was used to identify FAM134B promoter methylation in colorectal adenomas (N = 32), colorectal adenocarcinomas (N = 164), matched adjacent non‐neoplastic colorectal mucosae (N = 83) and colon cancer cell lines (N = 4). FAM134B expression was studied by real‐time quantitative polymerase chain reaction, immunohistochemistry, and Western blots. FAM134B promoter methylation was more frequent in adenocarcinomas (52%; 85/164) when compared to that of adenomas (28%; 9/32) and non‐neoplastic mucosae (35%; 29/83). Cancer cells exhibited higher methylation when compared to non‐neoplastic cells. FAM134B promoter methylation was inversely correlated with low FAM134B copy number and mRNA/protein expressions, whereas in‐vitro demethylation has restored FAM134B expression in colon cancer cells. FAM134B promoter methylation was associated with high histological grade (P = .025), presence of peri‐neural infiltration (P = .012), lymphovascular invasion (P = .021), lymph node metastasis (P = .0001), distant metastasis (P = .0001) and advanced pathological stages (P = .0001). In addition, FAM134B promoter methylation correlated with cancer recurrence and poor survival rates of patients with colorectal adenocarcinomas. To conclude, FAM134B promoter methylation plays a key role in regulating FAM134B expression in vitro and in vivo, which in turn contributes to the prediction of the biological aggressiveness of colorectal adenocarcinomas. Furthermore, FAM134B methylation might act as a marker in predicting clinical prognosis in patients with colorectal adenocarcinomas.

MiR-142-5p act as an oncogenic microRNA in colorectal cancer: Clinicopathological and functional insights

OBJECTIVES miR-142-5p was noted aberrantly expressed and plays important roles in different pathophysiological conditions in human. The present study aims to examine the expression of miR-142-5p and its association with clinicopathological factors in a large cohort of patients with colorectal cancer. In addition, the cellular effects of miR-142-5p and its interacting targets in colon cancer cells were investigated. METHODS Expression of miR-142-5p in colorectal cancer tissues (n=125) and colon cancer cell lines were analysed using real-time polymerase chain reaction. In vitro assays (cell proliferation, wound healing and colony formation) were used to study the miR-142-5p induced cellular effects. Western blots were used to examine the modulation of FAM134B, KRAS, EPAS1 and KLF6 proteins expression followed by miR-142-5p expression-manipulation. RESULTS Significant high expression of miR-142-5p was noted in cancer tissues and cells when compared to the controls (p<0.001). Overexpression of miR-142-5p in patients with colorectal cancer was common (72%; 90/125). miR-142-5p overexpression was associated with cancer in the proximal colorectum and with B-raf positive patients (p=0.05). Exogenous overexpression of miR-142-5p resulted in significantly increased cell proliferation, colony formation, and wound healing capacities, whereas inhibition of endogenous miR-142-5p led reduced cancer growth properties. The cellular effects of miR-142-5p were mediated by the modulation of tumour suppressor KLF6 expression, as the expression of miR-142-5p and KLF6 protein are inversely correlated in colon cancer cells. CONCLUSION High miR-142-5p expression was associated with the biological aggressiveness of cancer. Thus, suppression of miR-142-5p could be a therapeutic strategy for patients with colorectal cancers.

Harvest of lymph nodes in colorectal cancer depends on demographic and clinical characteristics of the patients

PurposeThis study aims to study the impact of clinical factors on the lymph node sampling in a large cohort of patients with colorectal cancer.MethodsA colorectal cancer database of 2298 patients in Queensland, Australia, was established. Zero-inflated regression method was used to model positive lymph node counts given the number of lymph nodes examined, with patient’s demographic and clinical factors as covariates in the model. Sensitivity and survival analyses were performed to illustrate the applicability of the recommendation of the minimum number of lymph nodes need to be pathologically examined.ResultsYounger patients with a larger sized tumour located at the left colon or rectum require fewer lymph nodes to be pathologically examined. Overall, 45.9% of the patients require eight or nine lymph nodes and 31.5% needs ten or 11 lymph nodes to be harvested for pathological examination. A simple formula could be used to obtain the minimum number of lymph node sampling required in patients with colorectal cancer based on patients’ age as well as site and dimension of the cancer.ConclusionsThe findings provide practical information about that the minimum number of lymph nodes that could be harvested at the time of collection of lymph nodes for pathological examination for patients with colorectal cancer. The minimum number of lymph nodes harvested depends on demographic (age) and clinical (location and dimension of cancer) characteristics of the patients with colorectal cancer.

Clinical and biological significance of miR-193a-3p targeted KRAS in colorectal cancer pathogenesis

This study was to investigate the expression pattern, mechanisms and clinicopathological implications of miR-193a-3p in colorectal cancer. Fresh-frozen tissues from 70 matched colorectal adenocarciomas and the adjacent non-neoplastic mucosae were prospectively collected. Two colorectal cancer cell lines (SW480 and SW48) and a non-neoplastic colon cell line (FHC) were also used. The expression levels of miR193a-3p in the cells and tissues were measured by quantitative real-time polymerase chain reaction. The expression of KRAS protein as a predicted downstream target for miR-193a was studied by immunohistochemistry. Restoration of the miR-193a level in the cell lines by permanent transfection was achieved and multiple functional and immunological assays were performed to analyze the functions of miR-193a in vitro. Down-regulation of miR-193a-3p was noted in 70% of the colorectal cancer tissues when compared to non-neoplastic colorectal tissues. In addition, down-regulation of miR-193a was significantly correlated with carcinoma of early stages (P<.05). Significant inverse correlation between miR-193a-3p and its target KRAS protein was determined (P<.05). Overexpression of miR-193a in colon cancer cells resulted in reduced cell proliferation, increased apoptosis, induced significant changes in cell cycle events and decreased the expression of epithelial-mesenchymal transition marker TWIST. This study confirms the tumor suppressor roles of miR-193a-3p, its downstream target affinity to KRAS and clinical significance in patients with colorectal adenocarcinoma.

Expression of GAEC1 mRNA and protein and its association with clinical and pathological parameters of patients with colorectal adenocarcinoma

AIM GAEC1 (Gene amplified in esophageal cancer 1) is an oncogene with key regulatory roles in the pathogenesis of oesophageal and colorectal carcinomas. The aim of this study was to investigate expression profiles and clinicopathological significance of GAEC1 mRNA and protein in patients with colorectal carcinomas. METHOD Matched cancer and non-cancer fresh frozen tissues were prospectively collected from 80 patients diagnosed with colorectal adenocarcinoma (39 men and 41 women). The tissues were sectioned for RNA extraction and cDNA conversion and quantified by a real-time polymerase chain reaction. GAEC1 protein expression was analysed by immunohistochemistry using a custom made GAEC1 antibody. RESULT GAEC1 mRNA was upregulated in majority (52%, n=42/80) of the colorectal carcinomas when compared to the matched non-neoplastic tissues. High expression of GAEC1 mRNA as correlated with patients of younger age (p=0.008), with lower grade carcinoma (p=0.028), presence of synchronous adenocarcinomas (p=0.034) and without any associated adenomas (p=0.047). In addition, patients with high GAEC1 mRNA overexpression had a shorter survival time. Furthermore, high GAEC1 protein expression was noted among patients having perforated colorectal carcinoma (p=0.04). CONCLUSION The high expression of GAEC1 mRNA/protein as well as its correlation with multiple clinicopathological characteristics in patients with colorectal carcinoma strongly suggests that GAEC1 is a key regulator in the initiation of colorectal carcinogenesis.

Tumour suppressor properties of miR-15a and its regulatory effects on BCL2 and SOX2 proteins in colorectal carcinomas

Objectives: In this study, we aimed to investigate the expression pattern, clinicopathological significance and tumour suppressive properties of miR‐15a in patients with colorectal carcinomas. Methods: Tissue samples from 87 patients with primary colorectal carcinomas, 50 matched metastatic lymph node and 37 non‐neoplastic colon (control) were prospectively recruited. The expression level of miR‐15a was measured by quantitative real‐time polymerase chain reaction. Restoration/overexpression of the miR‐15a was achieved by exogenous transfection. Four colon cancer cell lines (SW480, CaCO2, SW48 and HCT116) and a non‐cancer colon cell line (FHC) were also used for examining the miR‐15a induced tumour suppression properties using various in‐vitro and immunological assays. Results: Downregulation of miR‐15a was noted in ˜ 62% of the colorectal carcinoma tissues and it was positively correlated with the presence of cancer recurrence in patients with colorectal carcinomas (p = 0.05). Also, these patients with low miR‐15a expression showed relatively shorter survival time when compared to those with miR‐15a overexpression. Following miR‐15a exogenous overexpression, colon cancer cells showed reduced cell proliferation, low colony formation, less cell invasion properties and mitochondrial respiration when compared to control cells. In addition, BCL2 and SOX2 proteins showed a significant downregulation following miR‐15a overexpression suggesting its regulatory role in cancer growth, apoptosis and stemness. Conclusion: This study has confirmed the tumour suppressor properties of miR‐15a in colorectal cancers. Therefore, its modulation has potential implications in controlling various biological and pathogenic processes in colon carcinogenesis via targeting its downstream proteins such as BCL2 and SOX2. HighlightsDownregulation of miR‐15a was noted with colon cancer cell lines and patients with colorectal adenocarcinomas.Expression levels of miR‐15a was significantly altered with their matched metastatic lymph node tissues.MiR‐15 exhibits tumour suppressive properties in‐vitro via controlling cell growth and mitochondrial respiration.MiR‐15a expresses its regulatory roles in cancer cell growth, apoptosis and stemness via BCL2 and SOX2 modulation.