Application of Immunohistochemistry in Papillary Thyroid Carcinoma.

Immunohistochemistry (IHC) is an economic and precise method to localize the presence of specific protein at cellular level in tissue. Although many papillary thyroid carcinomas do not require IHC to render a diagnosis, there are certain scenarios in which IHC are important. The major diagnostic applications of IHC include confirmation of papillary thyroid carcinoma in sites other than the thyroid, distinguish papillary thyroid carcinoma from other primary thyroid neoplasms in thyroid, and identify papillary thyroid carcinoma from secondary tumors to the thyroid. At research level, IHC could help identify prognostic information, identify underlying genetic alterations, and predict response to treatment in papillary thyroid carcinoma. The understanding of principle and recent advances in IHC will improve the diagnosis and management of patients with thyroid lesions including papillary thyroid carcinoma.

Hemin, a major heme molecule, induced cellular and genetic alterations in normal colonic and colon cancer cells.

Heme, a molecule abundant in red meat, is assumed to exert carcinogenic effects on normal colonic cells and tumour suppressive effects on cancer cells, though the hypothesis has not been explicitly proven yet. The present study aims to investigate hemin induced cytotoxic, genetic and biological alterations in both normal and cancerous colonic epithelial cells, which may imply its carcinogenic and anticarcinogenic properties. Normal colonic epithelial cells and colon carcinoma cells were treated with a 0-500 µM concentration of hemin for 1-4 days following which cytotoxicity and wound healing assays, western blot, rt-PCR and cell cycle analysis were performed. Interestingly, hemin was cytotoxic to normal colonic cells, but carcinoma cells were more resistant. Cell migration potential of both normal colonic cells and colon carcinoma cells was impeded by hemin. Hemin caused upregulation of both P53 and ß-catenin gene and proteins expression in normal colonic cells with concomitant cell cycle arrest at G1(Gap 1) and G2/M (Gap 2/ Mitosis). G1 and G2 cell cycle arrests were also observed in colon carcinoma cells. In conclusion, the present study confirms that hemin, a main heme molecule present in red meat, facilitates behavioural, genetic and cell cycle kinetic alterations in both normal colonic epithelial and colon carcinoma cells.

Overexpression of family with sequence similarity 134, member B (FAM134B) in colon cancers and its tumor suppressive properties in vitro.

This study aims to investigate the overexpression-induced properties of tumor suppressor FAM134B (family with sequence similarity 134, member B) in colon cancer, examine the potential gene regulators of FAM134B expression and its impact on mitochondrial function. FAM134B was overexpressed in colon cancer and non-neoplastic colonic epithelial cells. Various cell-based assays including apoptosis, cell cycle, cell proliferation, clonogenic, extracellular flux and wound healing assays were performed. Western blot analysis was used to confirm and identify potential interacting partners of FAM134B in vitro. Immunohistochemistry and qPCR were employed to determine the expressions of MIF and FAM134B, respectively, on 63 patients with colorectal carcinoma. Results showed that FAM134B is involved in the cell cycle and mitochondrial function of colon cancer. Overexpression of FAM134B was coupled with increased expression levels of APC, p53, and MIF. Increased expression of both APC and p53 further validates the potential role of tumor suppressor FAM134B in regulating cancer progression through the WNT/ß-catenin signaling pathway. In approximately 70% of the patients with colorectal cancer, FAM134B downregulation was correlated with MIF protein overexpression while the remaining 30% showed concurrent expression of FAM134B and MIF (P = .045). High expression of MIF coupled with low expression of FAM134B is associated with microsatellite instability status in colorectal carcinomas (P = .049). FAM134B may exert its tumor suppressive function through affecting cell cycle, mitochondrial function via potentially interacting with MIF and p53.

Characterization of Mucosa-Associated Microbiota in Matched Cancer and Non-neoplastic Mucosa From Patients With Colorectal Cancer.

Colonic microbiota play important roles in the development of colorectal cancer. We aim to characterise the mucosa-associated microbiota in the tumour as well as the matched non-neoplastic mucosa from patients with colorectal cancer. Microbiota profiling in these samples was done using high-throughput 16S rRNA amplicon sequencing. Our results showed that the microbiota richness and diversity were similar between the tumour and non-neoplastic mucosae. Linear discriminant analysis effect size (LEfSe) analysis identified Fusobacterium and Campylobacter as the key genera of the tumour while Brevundimonas as the key genus of the non-neoplastic mucosa. In patients with shorter survival period, the relative abundance of Fusobacterium and Campylobacter was significantly higher in the tumour. Besides, regardless of the sites, tumour showed higher abundance of Fusobacterium. On the other hand, the relative abundance of Brevundimonas was significantly lower in the tumour. When validated with quantitative ddPCR, we found the absolute numbers of both Fusobacterium and F. nucleatum were significantly higher in the carcinoma from patients with shorter survival period, conventional type of adenocarcinoma in the distal portion of the large intestine (descending colon, sigmoidal colon, and rectum). In conclusion, our study showed a compositional alteration in the mucosa-associated microbiota in the tumour, which may contribute to the progression of colorectal cancer.

GAEC1 drives colon cancer progression.

Gene amplified in esophageal cancer 1 (GAEC1) expression and copy number changes are frequently associated with the pathogenesis of colorectal carcinomas. The current study aimed to identify the pathway and its transcriptional factors with which GAEC1 interacts within colorectal cancer, to gain a better understanding of the mechanics by which this gene exercises its effect on colorectal cancer. Two colonic adenocarcinoma cell lines (SW48 and SW480) and a nonneoplastic colon epithelial cell line (FHC) were transfected with GAEC1 to assess the oncogenic potential of GAEC1 overexpression. Multiple in vitro assays, including cell proliferation, wound healing, clonogenic, apoptosis, cell cycle, and extracellular flux, were performed. Western blot analysis was performed to identify potential gene-interaction partners of GAEC1 in vitro. Results showed that the overexpression of GAEC1 significantly increased cell proliferation, migration, and clonogenic potential ( P < 0.05) of colonic adenocarcinoma. Furthermore, GAEC1 portrayed its ability to influence mitochondrial respiration changes. The observations were in tandem with a significant increase in the expression of phosphorylated protein kinase B, forkhead box O3, and matrix metallopeptidase 9. Thus, GAEC1 has a role in regulating gene pathways, potentially in the Akt pathway. This could help in developing targeted therapies in the future.

Roles of long-non-coding RNAs in cancer therapy through the PI3K/Akt signalling pathway.

The vital need for Akt in maintaining basic cellular function has highlighted its importance in carcinogenesis. Unfortunately, Akt inhibitor development outcome has remained poor, as most of them have failed to show significant clinical benefit to cancer patients during the clinical trials. Recently, a new class of non-coding RNAs, known as long non-coding RNAs (lncRNAs), which show high tissue specificity, have demonstrated great influence in cancer progression and/or cancer inhibition. As both Akt signalling pathways and lncRNAs play such innate roles in carcinogenesis, identifying the specific roles that these lncRNAs play within this pathway may represent a novel research avenue for developing Akt inhibitors with better therapeutic properties. In addition, understanding the diverse mechanism by which lncRNAs regulate gene expression can assist in deciphering the fundamentals of carcinogenesis. The focus of interest should be on the lncRNAs, which affect Akt and finding the link between lncRNAs and Akt pathways associated with carcinogenesis. LncRNAs within the Akt pathways could affect multiple pathways in a particular cancer type, which ultimately creates an intricate web of connections between the pathways. In summary, lncRNAs have tremendous potential in cancer diagnosis, assessing cancer patient prognosis and in developing new therapeutic options for patients with resistance to current cancer therapies. Thus, understanding how lncRNAs influence the Akt pathway is essential for the development of novel and effective cancer therapies.

GAEC1 mutations and copy number aberration is associated with biological aggressiveness of colorectal cancer.

GAEC1 (gene amplified in oesophageal cancer 1) is a transforming oncogene with tumorigenic potential observed in both oesophageal squamous cell carcinoma and colorectal cancer. Nonetheless, there has been a lack of study done on this gene to understand how this gene exert its oncogenic properties in cancer. This study aims to identify novel mutation sites in GAEC1. To do so, seventy-nine matched colorectal cancers were tested for GAEC1 mutation via Sanger sequencing. The mutations noted were investigated for the correlations with the clinicopathological parameters of the patients with the cancer. Additionally, GAEC1 copy number aberration (CNA), mRNA and protein expression were determined with the use of droplet digital (dd) polymerase chain reaction (PCR), real-time PCR and Western blot (confirmed with immunofluorescence analysis). GAEC1 mutation was noted in 8.8% (n = 7/79) of the cancer tissues including one missense mutation, four loss of heterozygosity (LOH) and two substitutions. These mutations were significantly associated with cancer perforation (p = 0.021). GAEC1 mutation is frequently associated with increased GAEC1 protein expression. Nevertheless, GAEC1 mRNA and protein are only weakly associated. Taken together, GAEC1 mutation affects GAEC1 expression and is associated with poorer clinical outcomes. This further strengthens the role of GAEC1 as an oncogene.

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.

Novel FAM134B mutations and their clinicopathological significance in colorectal cancer.

FAM134B is a putative tumour suppressor gene and no mutations in FAM134B have been reported in colorectal cancer (CRC) to date. This study aims to identify FAM134B mutation sites and the clinicopathological significance of the gene in patients with CRC. Eighty-eight colorectal cancers were studied for FAM134B mutations by Sanger sequencing. The mutations in these cancers were then tested for correlations with the clinical and pathological parameters of the studied cancers. In addition, mRNA and protein expression of FAM134B in colorectal cancers was examined by polymerase chain reaction, Western blots, and immunofluorescence analysis. FAM134B mutation was noted in 46.5% (41/88) of patients with CRC. Thirty-one novel potentially pathogenic mutations were noted in coding and intronic regions of FAM134B in CRC, the majority of which were single-nucleotide substitutions. Of the 31 mutations, eight novel frameshift mutations showed potential to cause non-sense-mediated mRNA decay (NMD) in computational analysis. In addition, FAM134B mutations were associated with various clinical and pathological variables, including sex of the patients, presence of metachronous cancer, size, T staging, presence of distant metastases, and positivity of microsatellite instability (MSI) in the cancer (p < 0.05). FAM134B mRNA and protein expression was decreased in FAM134B mutated cancers. To conclude, FAM134B mutation is common in colorectal cancer. The association of the mutation of this gene with adverse clinical and pathological parameters is congruent with the tumour suppressive properties of the gene.

MicroRNAs serving as potential biomarkers and therapeutic targets in nasopharyngeal carcinoma: A critical review.

Despite significant medical advancement, nasopharyngeal carcinoma (NPC) remains one of the most difficult cancers to detect and treat where it continues to prevail especially among the Asian population. miRNAs could act as tumour suppressor genes or oncogenes in NPC. They play important roles in the pathogenesis of NPC by regulating specific target genes which are involved in various cellular processes and pathways. In particular, studies on miRNAs related to the Epstein Barr virus (EBV)-encoded latent membrane protein one (LMP1) and EBVmiRNA- BART miRNA confirmed the link between EBV and NPC. Both miRNA and its target genes could potentially be exploited for prognostic and therapeutic strategies. They are also important in predicting the sensitivity of NPC to radiotherapy and chemotherapy. The detection of stable circulating miRNAs in plasma of NPC patients has raised the potential of miRNAs as novel diagnostic markers. To conclude, understanding the roles of miRNA in NPC will identify ways to improve the management of patients with NPC.