MicroRNA polymorphism: A target for diagnosis and prognosis of hepatocellular carcinoma?

Tumor protein 53 gene polymorphism, demographic attributes and associated risk factors among liver cancer patients in Calabar, Nigeria

Mutations in the TP53 gene had been attributed to the development of liver cancer. Hepatocellular carcinoma (HCC) and liver tumour are liver diseases having high mortality rates in several populations. There is no information on the TP53 gene polymorphism among liver diseases patients in Calabar, Nigeria. This study investigated the genetic polymorphism of TP53 among HCC and liver tumour in Calabar. This research was carried out in the University of Calabar Teaching Hospital, Calabar. Blood samples were collected from 35 clinically diagnosed hepatocellular carcinoma and 10 tumour patients and 10 healthy controls. DNA was extracted from all blood samples and Polymerase Chain Reaction (PCR) was performed using specific primers. The PCR amplicons were digested using Hae III restriction enzyme and the genotypic and allelic frequencies was determined. Demographic data among participants showed that males were 68.9% (31), females (31.1%; 14), sex ratio (2.2: 0.5), mean age was 41.51 ± 2.13 years with an odds ratio of 1.25. The distribution of participants according to marital status were 33(73.3%), 10(22.2%), and 2(4.4%) for married, single, and widowed respectively. The participants were from different extractions with varied representations of Yakurr (22.2%, 10), Efik (20%, 9), Boki (13.3%, 6), Ogoja (13.3%, 6), Annang (8.8%, 4), Ibibio (2.2%, 1) and Igbo (2.2%, 1) and respectively. Approximately, 64.7% (30) of the chronic liver diseases were from the Central and Northern part of Cross River State. The risk factors were HCV infection, HBsAg+, alcoholism, smoking, consumption of groundnuts that may have been contaminated with aflatoxin and family history of the disease. PCR product yielded 254 bp and digested PCR product showed homozygous TT mutation (27), heterozygous GT mutation (17) and homozygous GG wild type (1) in cases. The overall TP53 gene mutation frequency was 46.32% (44). The frequency of G allele, T allele, GG, GT and TT were 0.21, 0.79, 0.04, 0.33 and 0.62 respectively among cases, while GG (wild type) was only detected among controls in the study population. The genotypic and allelic frequencies conform to Hardy-Weinberg equilibrium meaning that the forces of evolution were not acting on the locus. There were significant differences in the genotypic proportions of the TP53 gene polymorphism among patients and controls. This study on the TP53 gene polymorphism will serve as baseline information on the molecular etiology of hepatocellular carcinoma and liver tumour in Cross River State.

MicroRNAs as Diagnostic Tools in Hepatocellular Carcinoma

Liver cancer is the fourth leading cause of cancer-related deaths worldwide, with hepatocellular carcinoma (HCC) accounting for approximately 80% of all liver cancers. The serum concentration of alpha-fetoprotein (AFP) is the only validated biomarker for HCC diagnosis. MicroRNAs (miRNAs) are small non-coding RNAs of 21–30 nucleotides playing a critical role in human carcinogenesis, with types of miRNAs with oncogenic (oncomiRs) or tumor suppressor features. The altered expression of miRNAs in HCC is associated with many pathological processes, such as cancer initiation, tumor growth, apoptosis escape, promotion of migration and invasion. Moreover, circulating miRNAs have been increasingly investigated as non-invasive biomarkers for HCC diagnosis. MiRNAs’ expression patterns are altered in HCC and several single miRNAs or miRNAs panels have been found significantly up or downregulated in HCC with respect to healthy controls or non-oncological patients (cirrhotic or with viral hepatitis). However, any of the investigated miRNAs or miRNAs panels has entered clinical practice so far. This has mostly to do with lack of protocols standardization, small sample size and discrepancies in the measurement techniques. This review summarizes the major findings regarding the diagnostic role of miRNAs in HCC and their possible use together with standard biomarkers in order to obtain an early diagnosis and easier differential diagnosis from non-cancerous liver disease.

Genetic expression and mutational profile analysis in different pathologic stages of hepatocellular carcinoma patients

BACKGROUND

The clinical pathologic stages (stage I, II, III-IV) of hepatocellular carcinoma (HCC) are closely linked to the clinical prognosis of patients. This study aims at investigating the gene expression and mutational profile in different clinical pathologic stages of HCC.

METHODS

Based on the TCGA-LIHC cohort, we utilized a series of analytical approaches, such as statistical analysis, random forest, decision tree, principal component analysis (PCA), to identify the differential gene expression and mutational profiles. The expression patterns of several targeting genes were also verified by analyzing the Chinese HLivH060PG02 HCC cohort, several GEO datasets, HPA database, and diethylnitrosamine-induced HCC mouse model.

RESULTS

We identified a series of targeting genes with copy number variation, which is statistically associated with gene expression. Non-synonymous mutations mainly existed in some genes (e.g.,TTN, TP53, CTNNB1). Nevertheless, no association between gene mutation frequency and pathologic stage distribution was detected. The random forest and decision tree modeling analysis data showed a group of genes related to different HCC pathologic stages, including GAS2L3 and SEMA3F. Additionally, our PCA data indicated several genes associated with different pathologic stages, including SNRPA and SNRPD2. Compared with adjacent normal tissues, we observed a highly expressed level of GAS2L3, SNRPA, and SNRPD2 (P = 0.002) genes in HCC tissues of our HLivH060PG02 cohort. We also detected the high expression pattern of GAS2L3, SEMA3F, SNRPA, and SNRPD2 in the datasets of GSE102079, GSE76427, GSE64041, GSE121248, GSE84005, and the qPCR assay using diethylnitrosamine-induced HCC mouse model. Moreover, SEMA3F and SNRPD2 protein were highly stained in the HCC tissues of the HPA database. The high expression level of these four genes was associated with the poor survival prognosis of HCC cases.

CONCLUSIONS

Our study provides evidence regarding the gene expression and mutational profile in different clinical pathologic stages of TCGA HCC cases. Identifying four targeting genes, including GAS2L3, SNRPA, SNRPD2, and SEMA3F, offers insight into the molecular mechanisms associated with different prognoses of HCC.