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Background: Repeat hepatectomy is an important treatment for patients with repeat recurrent hepatocellular carcinoma (HCC).Methods: This study was a multicenter retrospective analysis of 1,135 patients who underwent primary curative liver resection for HCC. One hundred recurrent patients with second hepatectomy were included to develop a nomogram to predict the risk of post-recurrence survival (PRS). Thirty-eight patients in another institution were used to externally validate the nomogram. Univariate and multivariate Cox regression analyses were used to identify independent risk factors of PRS. Discrimination, calibration, and the Kaplan–Meier curves were used to evaluate the model performance.Results: The nomogram was based on variables associated with PRS after HCC recurrence, including the tumor, node, and metastasis (TNM) stage; albumin and aspartate aminotransferase levels at recurrence; tumor size, site, differentiation of recurrences; and time to recurrence (TTR). The discriminative ability of the nomogram, as indicated by the C statistics (0.758 and 0.811 for training cohort and external validation cohorts, respectively), was shown, which was better than that of the TNM staging system (0.609 and 0.609, respectively). The calibration curves showed ideal agreement between the prediction and the real observations. The area under the curves (AUCs) of the training cohort and external validation cohorts were 0.843 and 0.890, respectively. The Kaplan–Meier curve of the established nomogram also performed better than those of both the TNM and the BCLC staging systems.Conclusions: We constructed a nomogram to predict PRS in patients with repeat hepatectomy (RH) after repeat recurrence of HCC.

Regulatory factor X-5 (RFX5) represents a key transcription regulator of MHCII gene expression in the immune system. This study aims to explore the molecular mechanisms and biological significance of RFX5. Firstly, by analyzing ENCODE chromatin immunoprecipitation (ChIP)-seq in HepG2 and TCGA RNA-seq data, we discovered lysine-specific demethylase 4A (KDM4A), also named JMJD2A, to be a major downstream target gene of RFX5. Moreover, RFX5 was verified to bind directly to the KDM4A’s promoter region and sequentially promoted its transcription determined by the ChIP-PCR assay and luciferase assay. In addition, RFX5-dependent regulation of KDM4A was demonstrated in HCC. Compared with adjacent non-tumor tissues, the expression levels of KDM4A were significantly raised in HCC tumor tissues. Notably, elevated levels of KDM4A were strongly correlated with HCC patient prognosis. Functionally, KDM4A overexpression largely rescued the growth inhibitory effects of RFX5 deletion, highlighting KDM4A as a downstream effector of RFX5. Mechanistically, the RFX5-KDM4A pathway promoted the progression of the cell cycle from G0/G1 to S phase and was protective against cell apoptosis through regulation of p53 and its downstream genes in HCC. In conclusion, RFX5 could promote HCC progression via transcriptionally activating KDM4A expression.

Neoadjuvant chemotherapy (NAC) may provide survival benefits for patients with advanced esophageal squamous cell carcinoma. However, tumor cells can display primary or secondary resistance to paclitaxel (PTX), a primary component of induction chemotherapy regimen. To identify genes capable of conveying PTX resistance, we performed a genome-wide CRISPR transcriptional activation library in human KYSE-180 cells. High throughput next generation sequencing was further applied to establish the phenotype-to-genotype relationship. Our highest-ranking hits are CDKN1A, TSPAN4, ELAVL2, JUNB and PAAF1. We generated evidence that esophageal tumors with high CDKN1A, ELAVL2 and TSPAN4 levels, quantified using qRT-PCR and Western blot assays, showed poorer chemotherapy response. Higher expression levels of TSPAN4 and ELAVL2 protein are independent risk factors for poor chemotherapy response in ESCC patients. We then found that overexpression of CDKN1A, ELAVL2 or TSPAN4 in ESCC cell lines significantly promoted the resistance to PTX by inhibiting cell apoptosis. Interestingly, ESCC cells overexpressed CDKN1A, ELAVL2 or TSPAN4 also acquired resistance to cisplatin (DDP). This phenomenon may be explained by cross-resistance of chemotherapy. We additionally found an association between ELAVL2 and CDKN1A, which may be regarded as the upstream and downstream factors that synergistically involved in the regulation of chemo-resistance in ESCC. Therefore, our study demonstrated that the genome-wide CRISPR activation library is a powerful strategy for the discovery of chemo-resistant genes critical for ESCC and we reported the first evidence that the ELAVL2-CDKN1A axis may be an important mechanism involved in chemo-resistance in ESCC.