Kais Kasem

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.

JK1 (FAM134B) represses cell migration in colon cancer: a functional study of a novel gene

BACKGROUND JK1 is a novel cancer-related gene with unknown functional role in carcinogenesis. The aim of this study is to investigate the role of JK1 gene in carcinogenesis in an in vitro cell proliferation and migration analysis model. METHODS Small hairpin RNAs (shRNA) were designed to knock-down JK1 expression in colon cancer cell line (SW480) using transduction ready lentiviral particles. Cell proliferation and cell migration assays were performed on multiple extracellular matrices to investigate the cellular effects of JK1 in colon cancer cells. A non-cancer colonic epithelial cell line (FHC) was used to compare the expression of JK1 in cancer cell line. RESULTS JK1 knock-down did not affect cellular proliferation or survival in colon cancer. However, the manipulation increased cancer cell migration rates on collagen and fibronectin substrates. CONCLUSIONS JK1 was shown for the first time to have a functional role in the pathogenesis of colon cancer. The results imply that JK1 represses the capacity of cancer cells to migrate within their tissue. They also concurred with the previous findings of JK1 activity correlations with clinical and pathological features in colon cancer. The capacity may have utility as a means to prevent cancer cells forming metastases.

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.

Enhancing pathology learning experience of medical students using multiple advanced learning and teaching strategies.

Aim: Currently most medical schools use an integrated multidisciplinary approach in their curricula; therefore creating a huge challenge to engage medical students by delivering traditional pathology modules. In this study, we aimed to implement multiple advanced strategies to improve medical students’ pathology learning experience at Griffith University. Methods: Students enrolled in the second year of Griffith medical programme between 2011 and 2012 were invited to complete questionnaires rating the value and impact of resources delivered on their learning experience. In total, 272/ 290 students responded. The strategies adopted include virtual microscopy, web-based digitalised interactive modules, clinical scenario-integrated lectures, practical histology sessions and gross specimen demonstration. Quality and usefulness of the delivery of these modules were assessed using a 5 scale questionnaire. Results: In both years, overall score was high (mean score >4.5/ 5) for the histology lectures, clinical integrations and virtual microscopy sessions. The traditional delivery of practical and lecture sessions received lower scores. Qualitative comments suggested that the advanced methods were extremely useful for students’ learning experience of pathology. Discussion: A multidisciplinary approach by clinico-pathological integration and the use of virtual microscopy has the potential to better engage students to pathology learning in the modern medical curriculum.