MDIG-mediated H3K9me3 demethylation upregulates Myc by activating OTX2 and facilitates liver regeneration.

The mineral dust-induced gene (MDIG) comprises a conserved JmjC domain and has the ability to demethylate histone H3 lysine 9 trimethylation (H3K9me3). Previous studies have indicated the significance of MDIG in promoting cell proliferation by modulating cell-cycle transition. However, its involvement in liver regeneration has not been extensively investigated. In this study, we generated mice with liver-specific knockout of MDIG and applied partial hepatectomy or carbon tetrachloride mouse models to investigate the biological contribution of MDIG in liver regeneration. The MDIG levels showed initial upregulation followed by downregulation as the recovery progressed. Genetic MDIG deficiency resulted in dramatically impaired liver regeneration and delayed cell cycle progression. However, the MDIG-deleted liver was eventually restored over a long latency. RNA-seq analysis revealed Myc as a crucial effector downstream of MDIG. However, ATAC-seq identified the reduced chromatin accessibility of OTX2 locus in MDIG-ablated regenerating liver, with unaltered chromatin accessibility of Myc locus. Mechanistically, MDIG altered chromatin accessibility to allow transcription by demethylating H3K9me3 at the OTX2 promoter region. As a consequence, the transcription factor OTX2 binding at the Myc promoter region was decreased in MDIG-deficient hepatocytes, which in turn repressed Myc expression. Reciprocally, Myc enhanced MDIG expression by regulating MDIG promoter activity, forming a positive feedback loop to sustain hepatocyte proliferation. Altogether, our results prove the essential role of MDIG in facilitating liver regeneration via regulating histone methylation to alter chromatin accessibility and provide valuable insights into the epi-transcriptomic regulation during liver regeneration.

FLASH radiotherapy: A promising new method for radiotherapy.

Among the treatments for malignant tumors, radiotherapy is of great significance both as a main treatment and as an adjuvant treatment. Radiation therapy damages cancer cells with ionizing radiation, leading to their death. However, radiation-induced toxicity limits the dose delivered to the tumor, thereby constraining the control effect of radiotherapy on tumor growth. In addition, the delayed toxicity caused by radiotherapy significantly harms the physical and mental health of patients. FLASH-RT, an emerging class of radiotherapy, causes a phenomenon known as the 'FLASH effect', which delivers radiotherapy at an ultra-high dose rate with lower toxicity to normal tissue than conventional radiotherapy to achieve local tumor control. Although its mechanism remains to be fully elucidated, this modality constitutes a potential new approach to treating malignant tumors. In the present review, the current research progress of FLASH-RT and its various particular effects are described, including the status of research on FLASH-RT and its influencing factors. The hypothetic mechanism of action of FLASH-RT is also summarized, providing insight into future tumor treatments.

CircNFIB inhibits tumor growth and metastasis through suppressing MEK1/ERK signaling in intrahepatic cholangiocarcinoma.

BACKGROUND: Considerable evidence shows that circular RNAs (circRNAs) play an important role in tumor development. However, their function in intrahepatic cholangiocarcinoma (ICC) metastasis and the underlying mechanisms are incompletely understood. METHODS: circNFIB (hsa_circ_0086376, termed as cNFIB hereafter) was identified in human ICC tissues through circRNAs sequencing. The biological role of cNFIB was determined in vitro and in vivo by gain or loss of functional experiments. Fluorescence in situ hybridization (FISH), RNA immunoprecipitation (RIP) and RNA pull-down assays were conducted to analyze the interaction of cNFIB with dual specificity mitogen-activated protein kinase kinase1 (MEK1). Duolink in situ proximity ligation assay (PLA) and coimmunoprecipitation (co-IP) assay were used to investigate the effects of cNFIB on the interaction between MEK1 and mitogen-activated protein kinase 2 (ERK2). Finally, a series of in vitro and in vivo experiments were performed to explore the influences of cNFIB on the anti-tumor activity of trametinib (a MEK inhibitor). RESULTS: cNFIB was significantly down-regulated in human ICC tissues with postoperative metastases. The loss of cNFIB was highly associated with aggressive characteristics and predicted unfavorable prognosis in ICC patients. Functional studies revealed that cNFIB inhibited the proliferation and metastasis of ICC cells in vitro and in vivo. Mechanistically, cNFIB competitively interacted with MEK1, which induced the dissociation between MEK1 and ERK2, thereby resulting in the suppression of ERK signaling and tumor metastasis. Moreover, we found that ICC cells with high levels of cNFIB held the potential to delay the trametinib resistance. Consistently, in vivo and in vitro studies demonstrated that cotreatment with trametinib and lentivirus vector encoding cNFIB showed greater inhibitory effect than isolated trametinib treatment. CONCLUSIONS: Our findings identified that cNFIB played a key role in ICC growth and metastasis by regulating MEK1/ERK signaling. Given the efficacy of cNFIB modulation on ICC suppression and trametinib sensitivity, cNFIB appears to be a potential therapeutic molecule for ICC treatment.

Sarcopenia predicts an adverse prognosis in patients with combined hepatocellular carcinoma and cholangiocarcinoma after surgery.

BACKGROUND: The prognostic value of sarcopenia in combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) patients after surgery has not been evaluated, while the efficacy of the available tumor stage for cHCC-CC remains controversial. METHODS: All consecutive cHCC-CC patients after surgery were retrieved. The patients were stratified by the sex-specific medians of the psoas muscle index into groups with or without sarcopenia. Prognosis was analyzed using the Kaplan-Meier (K-M) method, and the K-M curves were adjusted by inverse probability weighting (IPW). A nomogram based on Cox regression analysis was established and further compared with primary liver cancer (PLC) stages by internal validation based on bootstrap resampling and k-fold cross-validation. RESULTS: A total of 153 patients were stratified into sarcopenia and non-sarcopenia groups. The sarcopenia group revealed statistically worse overall survival (OS) and disease-free survival (DFS) using the K-M method and K-M curves adjusted by IPW. Multivariate Cox regression analyses suggested sarcopenia as an independent risk factor for OS (HR = 1.55; p = 0.040) and DFS (HR = 1.55; p = 0.019). Subgroup analysis based on baseline variables showed sarcopenia as a stable risk factor for the prognosis. Our nomogram outperformed PLC stages in prognostic prediction, as evidenced by the best c-index, area under the curve, and positive improvement of the net reclassification index and integrated discrimination improvement. A fivefold cross-validation revealed consistent results. Decision curve analysis revealed higher net benefits of the nomogram than PLC stages. CONCLUSIONS: Sarcopenia is an independent and stable risk factor for the prognosis of cHCC-CC patients after surgery. Our nomogram might aid high-risk patient identification and clinical decisions.

IL-6-induced cGGNBP2 encodes a protein to promote cell growth and metastasis in intrahepatic cholangiocarcinoma.

BACKGROUND AND AIMS: IL-6-induced tumor progression has been well established through the induction of antiapoptotic and proliferative genes. However, whether other mechanisms such as IL-6 regulation of circular RNAs (circRNAs) may also contribute to tumor development remains unknown. APPROACH AND RESULTS: High-throughput RNA sequencing was used to identify the differentially expressed circRNAs on IL-6 stimulation in intrahepatic cholangiocarcinoma (ICC) cells. CircRNA GGNBP2 (derived from ggnbp2 gene, termed as cGGNBP2) was up-regulated by IL-6 treatment in a time and concentration-dependent manner. The biogenesis of cGGNBP2 was regulated by RNA-binding protein DEx-H Box Helicase 9, which was also mediated by IL-6 exposure. Mass spectrometry and western blotting identified a protein cGGNBP2-184aa encoded by cGGNBP2. cGGNBP2-184aa promoted ICC cell proliferation and metastasis in vitro and in vivo. Mechanistically, cGGNBP2-184aa directly interacted with signal transducers and activators of transduction-3 (STAT3), phosphorylated STAT3Tyr705 , and played a positive regulatory role in modulating IL-6/STAT3 signaling. IL-6/cGGNBP2-184aa/STAT3 formed a positive feedback loop to sustain constitutive activation of IL-6/STAT3 signaling. Elevated cGGNBP2 expression was correlated with poor prognosis of patients with ICC and was identified as an independent risk factor for patient prognosis. CONCLUSIONS: Our study demonstrates that cGGNBP2-184aa, a protein encoded by IL-6-induced cGGNBP2, formed a positive feedback loop to facilitate ICC progression and may serve as an auxiliary target for clinical IL-6/STAT3-targeting treatments in ICC.

Prediction of Prognosis for cHCC-CC Patients After Surgery: Comparison of Tumor Marker Score Based on AFP, CEA, CA19-9, and Other Clinical Stages.

BACKGROUND: The effectiveness of clinical stage as a prognostic factor in combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) patients is controversial. PATIENTS AND METHODS: Medical records of all pathologically confirmed cHCC-CC patients from 2000 to 2017 at West China Hospital were retrieved. Tumor marker score (TMS) was determined from optimal AFP, CEA, and CA19-9 cutoff values. Interaction and subgroup analysis were conducted according to potential confounders. Prognostic value of TMS and other prognostic models were evaluated by Kaplan-Meier (K-M) analysis, c-index, and time-dependent receiver operating curves (td-ROC). RESULTS: Optimal cutoff values for preoperative AFP, CEA, and CA19-9 were 10.76 ng/mL, 5.24 ng/mL, and 31.54 U/mL, respectively. Among 128 patients, 24, 58, and 46 were classified into TMS 0, TMS 1, and TMS ≥ 2, respectively. TMS could stratify our series into groups of statistically different prognosis. Subgroup analysis according to potential confounders and test for interactions showed that TMS 1 and TMS ≥ 2 were stable risk factors relative to TMS 0. Univariate (HR: TMS1 = 2.30, p = 0.014; TMS ≥ 2 = 5.1, p < 0.001) and multivariate Cox regression analyses (HR: TMS1 = 1.72, p = 0.124; TMS ≥ 2 = 4.15, p < 0.001) identified TMS as an independent prognostic risk factor. TMS had good discrimination (c-index 0.666, 95% CI 0.619-0.714), and calibration plots revealed favorable consistency. Area under the curve (AUC) value of td-ROC for TMS and integrated AUC was higher than for other clinical stages at any month within 5 years postoperation. CONCLUSION: TMS exhibited optimal prognostic value over other widely used clinical stages for cHCC-CC after surgery and may guide clinicians in prognostic prediction.

Nomogram Models for Predicting Risk and Prognosis of Newly Diagnosed Ovarian Cancer Patients with Liver Metastases - A Large Population-Based Real-World Study.

Background: Previous studies about liver metastases (LM) in newly diagnosed ovarian cancer (NDOC) patients based on Surveillance, Epidemiology, and End Results (SEER) program disregarded selection bias of missing data. Methods: We identified Data of NDOC patients from SEER between 2010 and 2016, presented a comprehensive description of this dataset, and limited possible biases due to missing data by applying multiple imputation (MI). We determined predictive factors for underlying LM development in NDOC patients and evaluated prognostic factors in NDOC patients with LM (OCLM). We then established predictive nomograms, assessed by the concordance index, calibration curve, decision curve analysis (DCA), and clinical impact curves (CIC). Results: The amount of missing data for different variables in SEER dataset ranges from 0 to 36.11%. The results between complete dataset and MI datasets are similar. LM prevalence in NDOC patients was 7.18%, and median overall survival for OCLM patients was 11 months. The C-index of risk nomogram for LM development in the training cohort (TC) and validation cohort (VC) were 0.764 and 0.759, respectively. The C-index and integrated area under curve within five years of prognostic nomogram for OCLM patients in the TC and VC were 0.743 and 0.773, 0.714 and 0.733, respectively. For both nomograms, DCA revealed favorable clinical use and calibration curves suggested good consistency. Conclusion: The risk nomogram is expected to aid clinicians in identifying high-risk groups of LM development in NDOC patients for intensive screening. The prognostic nomogram could facilitate individualized prediction and stratification for clinical trials in OCLM patients.

[Interference of Lumican Regulates the Invasion and Migration of Liver Cancer Cells].

OBJECTIVE: To explore the effect of silencing lumican on the invasion and migration of liver cancer cells. METHODS: Lumican was silenced by shRNA in liver cancer cells (HepG2 and MHCC97H). The mRNA levels of lumican were detected by qRT-PCR. Cell invasion was measured by Transwell. Cell migration was tested via wound healing. The protein levels of lumican,MMP-9,VEGF,ERK1,JNK,p-ERK1 and p-JNK were measured by Western blot. RESULTS: Liver cancer cells (HepG2 and MHCC97H) had higher levels of mRNA and protein of lumican compared with normal hepatocyte L02 (P<0.01). shRNA lowered the levels of mRNA and protein of lumican (P<0.01),and weakened the invasion and migration of cancer cells (P<0.01). The expressions of MMP-9 and VEGF decreased with the shRNA silence (P<0.01). shRNA also reduced the protein level of p-ERK1 and p-JNK (P<0.01). CONCLUSION: Silencing lumican by shRNA attenuates the invasion and migration of liver cancer cells via inhibiting the activation of ERK1/JNK pathway.