LncRNA H19 Regulates Breast Cancer DNA Damage Response and Sensitivity to PARP Inhibitors via Binding to ILF2.

Although DNA damage repair plays a critical role in cancer chemotherapy, the function of lncRNAs in this process remains largely unclear. In this study, in silico screening identified H19 as an lncRNA that potentially plays a role in DNA damage response and sensitivity to PARP inhibitors. Increased expression of H19 is correlated with disease progression and with a poor prognosis in breast cancer. In breast cancer cells, forced expression of H19 promotes DNA damage repair and resistance to PARP inhibition, whereas H19 depletion diminishes DNA damage repair and increases sensitivity to PARP inhibitors. H19 exerted its functional roles via direct interaction with ILF2 in the cell nucleus. H19 and ILF2 increased BRCA1 stability via the ubiquitin-proteasome proteolytic pathway via the H19- and ILF2-regulated BRCA1 ubiquitin ligases HUWE1 and UBE2T. In summary, this study has identified a novel mechanism to promote BRCA1-deficiency in breast cancer cells. Therefore, targeting the H19/ILF2/BRCA1 axis might modulate therapeutic approaches in breast cancer.

Preoperative tumor abnormal protein is a promising biomarker for predicting hepatocellular carcinoma oncological outcome following curative resection.

Introduction and Objectives: The objective of this study was to explore the potential relationship between tumor abnormal protein (TAP) and the prognosis of hepatocellular carcinoma (HCC) after a radical hepatectomy. Patients or Materials and Methods: This retrospective study included 168 HCC patients (tumor recurrence in 78 patients) who underwent a curative resection from January 2018 to June 2020. The whole population was categorized into a TAP high (≥224.6 µm2) or a TAP low group (<224.6 µm2). Results: There was no correlation between maximum tumor size and TAP. In the whole population or subgroups stratified by maximum tumor size, the recurrence-free survival (RFS) rate of the TAP low group was significantly higher than TAP high group (P < 0.05 for all). The multivariate analysis revealed that TAP (hazard ratio [HR], 3.47; 95% confidence interval [CI], 2.18-5.51; P < 0.001), large tumor size (HR, 2.18; 95% CI, 1.36-3.49; P < 0.001), poor tumor differentiation (HR, 0.53; 95% CI, 0.33-0.84; P = 0.007), and presence of microvascular invasion (MVI) (HR, 2.03; 95% CI, 1.28-3.22; P = 0.003) were independently associated with RFS. The prognostic implication of the nomogram incorporating TAP, maximum tumor diameter, tumor differentiation, and MVI was stronger than the model without TAP. Conclusion: The present study suggests that higher preoperative TAP is correlated with undesirable prognosis in HCC patients who underwent a radical hepatectomy. Our study provides a robust nomogram for RFS of postoperative HCC patients.

Prognostic role of tumor mutation burden in hepatocellular carcinoma after radical hepatectomy.

BACKGROUND AND AIM: This study aimed to assess the potential relationship between tumor mutation burden (TMB) and the recurrence risk of hepatocellular cancer (HCC) after curative resection and tried to develop a reliable TMB based nomogram. METHODS: This retrospective study was conducted in 128 patients (40 patients suffered from a recurrence of HCC) who had received radical hepatectomy by the same surgical team. A nomogram model was constructed using the R and EmpowerStats software. RESULTS: TMB was not associated with maximum tumor size and the presence of microvascular invasion (MVI). In the whole population or subgroups, the recurrence-free survival (RFS) rate was significantly lower in the TMB high group. In multivariate analysis, TMB (hazard ratio [HR], 10.12; 95% confidence interval [CI], 5.03-20.31; P < .001), large tumor diameter (HR, 2.91; 95% CI, 1.51-5.63; P = .001), presence of MVI (HR, 1.93; 95% CI, 1.03-3.65; P = .042) were independent predictors of RFS. The predictive power of the nomogram integrating TMB, tumor size and MVI was higher than model only incorporating tumor size and MVI. CONCLUSION: This study demonstrated for the first time that higher TMB was associated with poor prognosis in patients with HCC who had received curative resection, and a TMB based nomogram model had a well predictive performance for RFS in this population.

Preoperative Serum IL6, IL8, and TNF-α May Predict the Recurrence of Hepatocellular Cancer.

PURPOSE: As we all know, curative resection remains the only effective treatment for hepatocellular cancer (HCC). However, systemic inflammatory response syndrome always correlates with surgery, which may impose an impact on the clinical outcome of HCC patients who had undergone curative treatment. The present study is aimed at exploring the correlation between perioperative inflammatory mediators and recurrence risk of HCC. METHODS: This study retrospectively included 157 histologically confirmed single HCC patients (88 patients developed HCC again) who had received radical hepatectomy between January 2016 and May 2018 at the Department of Hepatobiliary Surgery, the People's Liberation Army General Hospital (PLAGH), China. The cut-off values for predicting recurrence were determined by receiver operating characteristic (ROC) curve analysis with estimation of the Youden index. Recurrence-free survival (RFS) was assessed using the Kaplan-Meier method, and the difference was compared between groups by the log-rank test. Univariate/multivariate analysis was performed to identify independent risk factors of postoperative tumor recurrence. RESULTS: The perioperative serum IL1, IL2, and IL10 levels showed no difference between groups, whereas the serum IL6, IL8, and TNF-α levels showed significant differences between groups. High preoperative serum IL6, IL8, and TNF-α levels were significantly associated with shorter RFS. Multivariate analysis revealed that preoperative serum IL6 > 8.45 pg/ml, preoperative serum IL8 > 68 pg/ml, preoperative serum TNF - α > 14.9 pg/ml, microvascular invasion (MVI), and maximum tumor size > 6 cm were independent predictors of RFS. CONCLUSIONS: The present study confirmed that high preoperative serum IL6, IL8, and TNF-α levels were distinctly correlated with the postoperative tumor recurrence risk of HCC patients.

The Predictive Role of Tenascin-C and Cellular Communication Network Factor 3 (CCN3) in Post Hepatectomy Liver Failure in a Rat Model and 50 Patients Following Partial Hepatectomy.

BACKGROUND Matricellular proteins of the extracellular matrix (ECM) include tenascin-C (TNC) and cellular communication network factor 3 (CCN3). This study aimed to investigate the role of TNC and CCN3 as prognostic factors for post hepatectomy liver failure (PHLF) in a rat model of partial hepatectomy and 50 patients following partial hepatectomy. MATERIAL AND METHODS Sprague-Dawley rats underwent 85% (n=53) or 90% hepatectomy (n=53) in the partial hepatectomy (PHx) model. TNC and CCN3 mRNA expression in residual liver tissue was evaluated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and enzyme-linked immunoassay (ELISA) determined the serum levels of TNC and CCN3. In 50 patients who underwent partial hepatectomy, TNC and CCN3 serum levels were measured on postoperative day 1 and day 3. RESULTS In the rat partial hepatectomy model, mRNA and serum levels of TNC and CCN3 were significantly increased within the first 24 h, and were higher in the 90% PHx group compared with the 85% PHx group. Fifty patients who underwent partial hepatectomy, included patients with PHLF (n=12) and patients without PHLF (n=38). Multivariate analysis confirmed that serum levels on postoperative day 3 TNChigh+CCN3high was a significant predictor of PHLF, which was associated with more than twice the risk of severe morbidity when compared with the low-risk patients (80% vs. 30%) and a significantly longer hospital stay (17 days vs. 8 days). CONCLUSIONS Further studies are needed to evaluate the potential role of the matricellular proteins, TNC and CCN3 as early clinical predictors for PHLF.

NUDT21 negatively regulates PSMB2 and CXXC5 by alternative polyadenylation and contributes to hepatocellular carcinoma suppression.

Alternative polyadenylation (APA) is an important post-transcriptional regulatory mechanism and involved in many diseases, including cancer. CFIm25, a subunit of the cleavage factor I encoded by NUDT21, is required for 3'RNA cleavage and polyadenylation. Although it has been recently reported to be involved in glioblastoma tumor suppression, its roles and the underlying functional mechanism remain unclear in other types of cancer. In this study, we characterized NUDT21 in hepatocellular carcinoma (HCC). Reduced expression of NUDT21 was observed in HCC tissue compared to adjacent non-tumorous compartment. HCC patients with lower NUDT21 expression have shorter overall and disease-free survival times than those with higher NUDT21 expression after surgery. Knockdown of NUDT21 promotes HCC cell proliferation, metastasis, and tumorigenesis, whereas forced expression of NUDT21 exhibits the opposite effects. We then performed global APA site profiling analysis in HCC cells and identified considerable number of genes with shortened 3'UTRs upon the modulation of NUDT21 expression. In particular, we further characterized the NUDT21-regulated genes PSMB2 and CXXC5. We found NUDT21 knockdown increases usage of the proximal polyadenylation site in the PSMB2 and CXXC5 3' UTRs, resulting in marked increase in the expression of PSMB2 and CXXC5. Moreover, knockdown of PSMB2 or CXXC5 suppresses HCC cell proliferation and invasion. Taken together, our study demonstrated that NUDT21 inhibits HCC proliferation, metastasis and tumorigenesis, at least in part, by suppressing PSMB2 and CXXC5, and thereby provided a new insight into understanding the connection of HCC suppression and APA machinery.

CCAR1 5' UTR as a natural miRancer of miR-1254 overrides tamoxifen resistance.

MicroRNAs (miRNAs) typically bind to unstructured miRNA-binding sites in target RNAs, leading to a mutual repression of expression. Here, we report that miR-1254 interacts with structured elements in cell cycle and apoptosis regulator 1 (CCAR1) 5' untranslated region (UTR) and this interaction enhances the stability of both molecules. miR-1254 can also act as a repressor when binding to unstructured sites in its targets. Interestingly, structured miR-1254-targeting sites act as both a functional RNA motif-sensing unit, and an independent RNA functional unit that enhances miR-1254 expression. Artificially designed miRNA enhancers, termed "miRancers", can stabilize and enhance the activity of miRNAs of interest. We further demonstrate that CCAR1 5' UTR as a natural miRancer of endogenous miR-1254 re-sensitizes tamoxifen-resistant breast cancer cells to tamoxifen. Thus, our study presents a novel model of miRNA function, wherein highly structured miRancer-like motif-containing RNA fragments or miRancer molecules specifically interact with miRNAs, leading to reciprocal stabilization.