Suja Pillai

Regulation of microRNA-1288 in colorectal cancer: altered expression and its clinicopathological significance

We aim to examine the miR‐1288 expression in cancer cell lines and a large cohort of patients with colorectal cancer. Two colon cancer cell lines (SW480 and SW48) and one normal colonic epithelial cell line (FHC) were recruited. The miRNA expressions of miR‐1288 were tested on these cell lines by using quantitative real‐time polymerase chain reaction (qRT‐PCR). An exogenous miR‐1288 (mimic) was used to detect cell proliferation and cell cycle changes in SW480 using MTT calorimetric assay and flow cytometry, respectively. In addition, tissues from 122 patients with surgical resection of colorectum (82 adenocarcinomas, 20 adenomas, and 20 non‐neoplastic tissues) were tested for miR‐1288 expression by qRT‐PCR. The colon cancer cell lines showed reduced expression of miR‐1288 compared to normal colonic epithelial cell line. Over expression of miR‐1288 in SW480 cell line showed increased cell proliferation and increased G2–M phase cells. In tissues, reduced miR‐1288 expression was noted in majority of colorectal adenocarcinoma compared to colorectal adenoma and non‐neoplastic tissues. Reduced or absent expression of miR‐1288 was noted in 76% (n = 62/82) of the cancers. The expression levels of miR‐1288 were higher in distal colorectal adenocarcinomas (P = 0.013) and in cancers of lower T staging (P = 0.033). To conclude, alternation of miR‐1288 expression is important in the progression of colorectal cancer. The differential regulation of miR‐1288 was found to be related to cancer location and pathological staging in colorectal cancers.

Diffuse sclerosing variant of papillary thyroid carcinoma—an update of its clinicopathological features and molecular biology

Diffuse sclerosing variant of papillary thyroid carcinoma (DSVPTC) is an uncommon variant of papillary thyroid carcinoma. The aim of this review is to critically analyse the features of this entity. A search of the literature revealed 25 clinicopathological studies with in-depth analysis of features of DSVPTC. Overall, the prevalence of DSVPTC varies from 0.7-6.6% of all papillary thyroid carcinoma. Higher prevalence of DSVPTC was noted in paediatric patients and in patients affected by irradiation. DSVPTC tends to occur more frequently in women and in patients in the third decade of life. Macroscopically, DSVPTC can involve the thyroid gland extensively without forming a dominant mass. Microscopic examination of DSVPTC revealed extensive fibrosis, squamous metaplasia and numerous psammoma bodies. The latter pathological feature can aid in the pre-operative diagnosis of the entity by fine needle aspiration and ultrasound. Compared to conventional papillary thyroid carcinoma, DSVPTC had a higher incidence of lymph node metastases at presentation. Distant metastases were noted in approximately 5% of the cases. Patients with DSVPTC were recommended to be managed by aggressive treatment protocols. It is likely that as a result of this, the prognosis of the patients with DSVPTC was noted to be similar to conventional papillary thyroid carcinoma. Overall, cancer recurrence and cancer related mortality have been reported in 14% and 3%, respectively, of patients with DSVPTC. In immunohistochemical studies, DSVPTC showed different expression patterns of epithelial membrane antigen, galectin 3, cell adhesion molecules, p53 and p63 when compared to conventional papillary thyroid carcinoma. On genetic analysis, the occurrence of BRAF and RAS mutations are uncommon events in DSVPTC and activation of RET/PTC rearrangements are common. To conclude, DSVPTC has different clinical, pathological and molecular profiles when compared to conventional papillary thyroid carcinoma.

Overexpression of microRNA-1288 in oesophageal squamous cell carcinoma

PURPOSE This study aims to examine the expression profiles miR-1288 in oesophageal squamous cell carcinoma (ESCC). The cellular implications and target interactions of ESCC cells following miR-1288 overexpression was also examined. METHODS In total, 120 oesophageal tissues (90 primary ESCCs and 30 non-neoplastic tissues) were recruited for miR-1288 expression analysis using qRT-PCR. An exogenous miR-1288 mimic and its inhibitor were used to explore the in-vitro effects of miR-1288 on ESCC cells by performing cell proliferation, colony formation, cell invasion and migration assays. Localisation and modulatory changes of various miR-1288 regulated proteins such as FOXO1, p53, TAB3, BCL2 and kRAS was examined using immunofluorescence and western blot. RESULTS Overexpression of miR-1288 was more often noted in ESCC tissues when compared to non-neoplastic oesophageal tissues. High expression was often noted in high grade carcinomas and with metastases. Patients with high levels of miR-1288 expression showed a slightly better survival compared to patients with low miR-1288 levels. Furthermore, overexpression of miR-1288 showed increased cell proliferation and colony formation, improved cell migration and enhanced cell invasion properties in ESCC cells. In addition, miR-1288 overexpression in ESCC cells showed repression of cytoplasmic tumour suppressor FOXO1 protein expression. Inversely, inhibition of miR-1288 expression exhibited remarkable upregulation of FOXO1 protein, while expressions of other tested proteins remain unchanged. CONCLUSIONS Up regulation of miR-1288 expression in ESCC tissues and miR-1288 induced oncogenic features of ESCC cells in-vitro indicates the oncogenic roles of miR-1288 in ESCCs. Overexpression of miR-1288 play a key role in the pathogenesis of ESCCs and its modulation may have potential therapeutic value in patients with ESCC.

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...

Review of sequencing platforms and their applications in phaeochromocytoma and paragangliomas

Genetic testing is recommended for patients with phaeochromocytoma (PCC) and paraganglioma (PGL) because of their genetic heterogeneity and heritability. Due to the large number of susceptibility genes associated with PCC/PGL, next-generation sequencing (NGS) technology is ideally suited for carrying out genetic screening of these individuals. New generations of DNA sequencing technologies facilitate the development of comprehensive genetic testing in PCC/PGL at a lower cost. Whole-exome sequencing and targeted NGS are the preferred methods for screening of PCC/PGL, both having precise mutation detection methods and low costs. RNA sequencing and DNA methylation studies using NGS technology in PCC/PGL can be adopted to act as diagnostic or prognostic biomarkers as well as in planning targeted epigenetic treatment of patients with PCC/PGL. The designs of NGS having a high depth of coverage and robust analytical pipelines can lead to the successful detection of a wide range of genomic defects in PCC/PGL. Nevertheless, the major challenges of this technology must be addressed before it has practical applications in the clinical diagnostics to fulfill the goal of personalized medicine in PCC/PGL. In future, novel approaches of sequencing, such as third and fourth generation sequencing can alter the workflow, cost, analysis, and interpretation of genomics associated with PCC/PGL.

Metastasis-suppressing NID2 , an epigenetically-silenced gene, in the pathogenesis of nasopharyngeal carcinoma and esophageal squamous cell carcinoma

Nidogen-2 (NID2) is a key component of the basement membrane that stabilizes the extracellular matrix (ECM) network. The aim of the study is to analyze the functional roles of NID2 in the pathogenesis of nasopharyngeal carcinoma (NPC) and esophageal squamous cell carcinoma (ESCC). We performed genome-wide methylation profiling of NPC and ESCC and validated our findings using the methylation-sensitive high-resolution melting (MS-HRM) assay. Results showed that promoter methylation of NID2 was significantly higher in NPC and ESCC samples than in their adjacent non-cancer counterparts. Consistently, down-regulation of NID2 was observed in the clinical samples and cell lines of both NPC and ESCC. Re-expression of NID2 suppresses clonogenic survival and migration abilities of transduced NPC and ESCC cells. We showed that NID2 significantly inhibits liver metastasis. Mechanistic studies of signaling pathways also confirm that NID2 suppresses the EGFR/Akt and integrin/FAK/PLCγ metastasis-related pathways. This study provides novel insights into the crucial tumor metastasis suppression roles of NID2 in cancers.

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.

Evaluation of multidisciplinary strategies and traditional approaches in teaching pathology in medical students: Evaluation of pathology teaching

This study aims to evaluate the impact on the implementation of multiple strategies to improve medical students pathology learning experience. In two consecutive years, medical students after a whole year of enrolling in pathology teaching, were invited to complete questionnaires rating and commenting on the personal learning experience of multiple teaching resources delivered in pathology. In both years, the overall score was high (mean score = 4.57 ± 0.63 /5) for the newly introduced sessions, namely histology lectures, clinical integrations and virtual microscopy pre‐practical sessions. However, this was only marginally different from that of traditional practical (mean = 4.37 ± 0.68/5) and pathology lecture sessions (mean = 4.42 ± 0.61 /5). In addition, 53% positive correlation was noted for the overall responses between virtual microscopy guided pathology modules and practical sessions indicating the benefit of virtual microscopy in better preparing students for these sessions (P < 0.001). Qualitative comments suggested that the virtual microscopy sessions along with clinical scenario based learning were extremely useful for students’ learning in pathology. To conclude, a multidisciplinary approach by clinical integration and flexibility in the mode of delivery by the use of virtual microscopy has the potential to better engage students to the learning of pathology.

DNA Genome Sequencing in Esophageal Adenocarcinoma

Next-generation sequencing refers to the high-throughput DNA sequencing technologies, which are capable of sequencing large numbers of different DNA sequences in a single/parallel reaction. It is a powerful tool to identify inherited and acquired genetic alterations associated with the development of esophageal adenocarcinoma. Whole-genome sequencing is the most comprehensive but expensive, whereas whole-exome sequencing is cost-effective but it only works for the known genes. Thus, second-generation sequencing methods can provide a complete picture of the esophageal adenocarcinoma genome by detecting and discovering different type of alterations in the cancer. This would help in diagnostics and will further help in developing personalized medicine in esophageal adenocarcinoma.