Precision medicine for hepatocellular carcinoma: driver mutations and targeted therapy Precision medicine for Hepatocellular Carcinoma: Driver mutations and targeted therapy

Background: MEIS2 has been identified as one of the key transcription factors in the gene regulatory network in the development and pathogenesis of human cancers. Our study aims to identify the regulatory mechanisms of MEIS2 in hepatocellular carcinoma (HCC), which could be targeted to develop new therapeutic strategies. Methods: The variation of MEIS2 levels were assayed in a cohort of HCC patients. The proliferation, clone-formation, migration, and invasion abilities of HCC cells were measured to analyze the effects of MEIS2C and MEIS2D (MEIS2C/D) knockdown with small hairpin RNAs in vitro and in vivo. Chromatin immunoprecipitation (ChIP) was performed to identify MEIS2 binding site. Immunoprecipitation and immunofluorescence assays were employed to detect proteins regulated by MEIS2. Results: The expression of MEIS2C/D was increased in the HCC specimens when compared with the adjacent noncancerous liver (ANL) tissues. Moreover, MEIS2C/D expression negatively correlated with the prognosis of HCC patients. On the other hand, knockdown of MEIS2C/D could inhibit proliferation and diminish migration and invasion of hepatoma cells in vitro and in vivo. Mechanistically, MESI2C activated Wnt/β-catenin pathway in cooperation with Parafibromin (CDC73), while MEIS2D suppressed Hippo pathway by promoting YAP nuclear translocation via miR-1307-3p/LATS1 axis. Notably, CDC73 could directly either interact with MEIS2C/β-catenin or MEIS2D/YAP complex, depending on its tyrosine-phosphorylation status. Conclusions: Our studies indicate that MEISC/D promote HCC development via Wnt/β-catenin and Hippo/YAP signaling pathways, highlighting the complex molecular network of MEIS2C/D in HCC pathogenesis. These results suggest that MEISC/D may serve as a potential novel therapeutic target for HCC.

Ki-67 is one of the most useful markers to evaluate cell proliferative activity and has been widely used in tumor treatment and research. However, its role in human laryngeal carcinoma remains poorly defined. The aim of the present study was to investigate the expression of Ki‑67 in human laryngeal squamous carcinoma and the effect of Ki‑67 gene silencing by small interfering (si)RNA on the proliferation of human laryngocarcinoma HEp2 cells. Immunohistochemistry and reverse transcription‑quantitative polymerase chain reaction were performed to examine the expression of Ki‑67 in human laryngeal squamous carcinoma tissues and adjacent non‑cancer tissues from 50 patients with laryngeal squamous carcinoma. RNA interference was used to knock down the expression of Ki‑67 in the HEp2 cell line, and the proliferation of the treated cells was observed in vitro. Western blot analysis was used to determine the expression levels of epidermal growth factor receptor (EGFR) and E‑cadherin in the treated cells. The expression of Ki‑67 in the laryngeal squamous carcinoma tissues was significantly higher than that of the adjacent non‑tumor tissues (P=0.028). The high expression of Ki‑67 in cancer was significantly correlated with cervical lymph node metastasis and clinical outcomes (all P<0.001). The silencing of Ki‑67 resulted in the inhibition of proliferation of the HEp2 human laryngocarcinoma cells (P<0.001). In addition, compared with the control group, the expression levels of EGFR and E‑cadherin in the Ki‑67 siRNA‑treated cells were significantly decreased (P<0.001) and increased (P<0.001), respectively. These results suggested that Ki‑67 is important in regulating the proliferation of human laryngocarcinoma HEp2 cells and that the mechanism may at least partially be associated with the upregulation of EGFR and the downregulation of E‑cadherin. Overall, Ki‑67 can be used as an important indicator for judging clinical progress and estimating prognosis in human laryngeal squamous carcinoma.

Laryngeal squamous cell carcinoma (LSCC) is an aggressive malignancy with highly mortality rate. Long non-coding RNA (lncRNA) AGAP2-AS1 is an identified oncogene in several types of cancers. However, the role of AGAP2-AS1 in LSCC remains unclear. The expression levels of AGAP2-AS1 in LSCC tissues and cell lines were measured using qRT-PCR. AGAP2-AS1 was knocked down in LSCC cells through transfection with siRNA-AGAP2-AS1. Cell proliferation and invasion were detected using MTT and transwell assays. Dual-luciferase reporter gene assay was performed to confirm the interaction with AGAP2-AS1 and downstream genes. Our results showed that AGAP2-AS1 expression was remarkably increased in human LSCC tissues and cell lines. Knockdown of AGAP2-AS1 significantly inhibited the proliferation and invasion of LSCC cells. In addition, AGAP2-AS1 sponged miR-193a-3p and regulated its expression in LSCC cells. Inhibition of miR-193a-3p reversed the effects of AGAP2-AS1 knockdown on LSCC cells. Furthermore, Lysyl oxidase-like 4 (LOXL4) was a target gene of miR-193a-3p and the role of miR-193a-3p was mediated by LOXL4. In conclusion, these findings suggest that knockdown of AGAP2-AS1 inhibited the proliferation and invasion of LSCC cells through regulating the miR-193a-3p/LOXL4 axis.

Purpose. Head and neck squamous cell carcinoma (HNSCC) is the most common malignant tumors in the world. Genetic variants have an important role in HNSCC progression. Our study is aimed at exploring the relationship between MIR17HG polymorphisms and HNSCC risk in the Chinese Han population. Methods. We recruited 537 HNSCC cases and 533 healthy subjects to detect the correlation of six polymorphisms in MIR17HG with HNSCC susceptibility. The associations were evaluated by computing odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression analysis. Results. Our study revealed that rs7336610 (OR 1.77, 95%CI = 1.09‐2.86, and p = 0.021) and rs1428 (OR 1.73, 95%CI = 1.07‐2.81, and p = 0.025) are strongly associated with increased susceptibility to HNSCC in men. Besides, rs17735387 played a crucial protective role in stage III/IV HNSCC patients (OR 0.34, 95%CI = 0.12‐0.95, and p = 0.040) compared with stage I/II. Conclusion. Our study firstly indicated that MIR17HG polymorphisms are significantly associated with HNSCC susceptibility, which suggests that MIR17HG has a potential role in the occurrence of HNSCC.

Anaplastic thyroid carcinoma (ATC) originates from completely undifferentiated cells, and is the most lethal type of thyroid-derived tumor. Numerous microRNAs have significant roles in tumorigenesis by targeting relevant genes. The role of microRNA 146b (miR-146b) in ATC remains to be elucidated. In order to characterize the role of miR-146b in ATC, overexpression or interference of miR-146b was induced in ATC cell lines, and cell proliferation and migration were evaluated. The potential targets of miR-146b were searched in the Gene Expression Omnibus database for ATC and matched non-tumor control samples. The expression level of potential targets was detected following overexpression or interference of miR-146b in ATC cell lines. In the present study, cell proliferation was promoted when overexpression of miR-146b was induced in ATC, and inhibited when interference of miR-146b was induced, which indicated that miR-146b affects the proliferation of ATC cells in vitro. In addition, cell migration of ATC was also affected by miR-146b. During the search for potential targets of miR-146b in ATC, p21 (also known as p21Waf1/Cip1 or CDKN1A) was noted for its role in cell cycle progression and tumor pathogenesis. The expression level of p21 was influenced by the level of miR-146b, and the results of the present study demonstrated that the level of p21 was increased when FRO cells were transformed with miR-146b mimic, and p21 was downregulated when FRO cells transformed with anti-miR-146b. In conclusion, p21 may participate in the regulation of ATC cell proliferation by miR-146b.