Hepatitis B virus mutations, expression quantitative trait loci for PTPN12, and their interactions in hepatocellular carcinoma

Protein tyrosine phosphatase non-receptor type 12 (PTPN12), negatively regulated by miR-106a-5p, suppresses the progression of hepatocellular carcinoma

Protein tyrosine phosphatase non-receptor type 12 (PTPN12) is abnormally expressed in many human cancers. However, its role in hepatocellular carcinoma (HCC) is indeterminate. In this study, immunohistochemistry and Western blot were adopted to detect PTPN12 protein expression in HCC tissues and cell lines. MiR-106a-5p and PTPN12 mRNA expressions were determined by quantitative real-time polymerase chain reaction (qRT-PCR). siRNA was used to knockdown PTPN12 expression in HCC cells, and the multiplication, migration, and invasion of HCC cells were determined by cell counting kit 8 (CCK-8) and Transwell assays. The interaction between PTPN12 and miR-106a-5p was verified by dual-luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay. In the present study, we demonstrated that PTPN12 expression in HCC tissues and cells was significantly decreased, which was associated with the tumor size, TNM stage, and lymph node metastasis of HCC patients. Functionally, knocking down PTPN12 significantly promoted the multiplication, migration, invasion, and epithelial-mesenchymal transition (EMT) of HCC cells. PTPN12 was identified as the direct target of miR-106a-5p, and its expression was negatively modulated by miR-106a-5p. Besides, PTPN12 counteracted the promoting effects of miR-106a-5p on the viability, migration, invasion, and EMT of HCC cells. In conclusion, this study substantiates that PTPN12 inhibits the growth, migration, invasion, and EMT of HCC cells, and miR-106a-5p contributes to its dysregulation in HCC.

Nonreceptor protein tyrosine phosphatases (NRPTPs) gene family associates with the risk of hepatocellular carcinoma in a Chinese hepatitis B virus-related subjects

Nonreceptor protein tyrosine phosphatases (NRPTPs) are reported to be associated with several human cancers, but their roles in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) remain unclear. Here, we integrated bioinformatics tools, population association analyses, and biological assays to systematically screen for potentially functional single nucleotide polymorphisms (SNPs) within the 17 NRPTPs genes and evaluate the effects of candidate SNPs on the risk of HCC or persistent HBV infection. A total of 790 HBV-related HCC cases and 1454 cancer-free controls were enrolled. Controls included 711 HBV persistent carriers and 743 spontaneously recovered subjects. Results demonstrated that PTPN4 rs9308777 (odds ratio [OR] = 1.25, 95% confidence interval [CI] = 1.06-1.49, P = .009) and PTPN12 rs350050 (OR = 1.26, 95% CI = 1.10-1.45, P = .001), were significantly associated with HCC risk, but not with persistent HBV infection risk. The cumulative risk effect of these two SNPs was more significantly increased the susceptibility to HCC (OR = 1.27, 95% CI = 1.14-1.41, P = 2.40 × 10^-5 ). Subsequent biological assays further revealed the potential pathogenesis that PTPN4 rs9308777 might decrease the gene expression, and PTPN12 rs3750050 might promote cell proliferation by attenuating PTPN12's inhibitory activity on EGFR/ERK pathway. In summary, our integrative study highlights that PTPN4 and PTPN12 are significantly associated with HBV-related HCC risk, but do not influence persistent HBV infection. These findings shed light on the importance of the synergistic effects of regulatory and missense variants on the risk for HCC, and provide data to support personalized cancer medicine in the future.

Long non‑coding RNAs in HBV‑related hepatocellular carcinoma (Review)

Hepatitis B virus (HBV)‑related hepatocellular carcinoma (HCC) is a global health problem that accounts for more than half of total liver cancer cases in developing countries. Despite the growing number of researches conducted, the molecular mechanism underlying the development of HCC remains elusive. Long non‑coding RNAs (lncRNAs), which are non‑coding RNAs >200 nt in length that were previously considered to be transcriptional noise, have been found to be dysregulated in HBV‑related HCC with the help of high‑throughput omics techniques. Subsequent investigations revealed that aberrant expression of lncRNAs may affect the risk of HBV‑related HCC through diverse mechanisms, including epigenetic silencing of transcriptional activation, alternative splicing, molecular sponging, modulating protein stability, and by serving as precursors of miRNAs. Although the sensitivity and specificity of lncRNAs must be further validated, a number of circulating lncRNAs have been identified as useful biomarkers for HBV‑related HCC. In addition to these findings, recent studies also unveiled that certain genetic polymorphisms in lncRNAs may affect the occurrence and prognosis of HBV‑related HCC. The aim of the present review was to provide an overview of the mechanisms underlying the involvement of lncRNAs in HBV‑related HCC. Subsequently, lncRNAs found to be dysregulated in HBV‑related HCC were focused on and current findings on circulating lncRNAs and their genetic polymorphisms were discussed.

PTPN12 Affects Nasopharyngeal Carcinoma Cell Proliferation and Migration Through Regulating EGFR

OBJECTIVE

Nasopharyngeal carcinoma (NPC) shows the leading morbidity in otorhinolaryngological malignant tumor. It is a common malignancy in China with obvious reginal distribution. NPC is a polygenic disease that is affected by numerous factors. Protein tyrosine phosphatase nonreceptor type 12 (PTPN12) regulates multiple tumor proliferation and development, including breast cancer and colon cancer. However, the role of PTPN12 in NPC occurrence and development has not been elucidated.

PATIENTS AND METHODS

NPC cell line CNE2 was cultured in vitro and divided into three groups, including control, empty plasmid, and PTPN12 groups. PTPN12 mRNA and protein expressions were tested by real-time polymerase chain reaction and Western blot. CNE2 cell proliferation was detected by MTT assay. Cell migration was determined by wound healing assay. Cell apoptosis was evaluated by caspase 3 activity detection. Epidermal growth factor receptor (EGFR) expression was assessed by Western blot.

RESULTS

PTPN12 plasmid transfection increased PTPN12 mRNA and protein expressions, suppressed cell proliferation and migration, reduced EGFR level, and enhanced caspase 3 activity compared with control and empty plasmid groups (p < 0.05).

CONCLUSIONS

PTPN12 regulates NPC proliferation and migration through negative regulating EGFR. It could be treated as a molecular target for NPC diagnosis and prognosis analysis.

Hepatitis B virus mutations, expression quantitative trait loci for PTPN12, and their interactions in hepatocellular carcinoma

Previously we identified that HBV(Hepatitis B virus) sequence variation, which may interact with host human leukocyte antigen (HLA) genetic variation, could influence host risk of hepatocellular carcinoma (HCC). More HBV‐host interactions need to be identified. Protein tyrosine phosphatase nonreceptor type 12 (PTPN12), serves as an antagonist to tyrosine kinase signaling, may play integral roles in immune response against HBV infection and the development of HCC. Rs11485985 was an expression quantitative trait loci (eQTL) for PTPN12 by bioinformatics analyses. In this study, we genotyped the PTPN12 eQTL and sequenced the HBV region EnhII/BCP/PC in a case–control cohort including 1507 HBV‐related HCC cases and 1560 HBV persistent carriers as controls. The variant genotype GG of rs11489585 increased HCC risk compared to the HBV persistent carriers (adjusted OR = 2.03, 95% confidence interval [CIs] = 1.30–3.18). We also detected borderline significant associations of PTPN12 eQTL rs11489585 with HBV mutations (P = 0.05 for G1799C). Taken together, PTPN12 may influence HCC risk accompanied by HBV mutations.