USP22 upregulates ZEB1-mediated VEGFA transcription in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common solid tumor with high rate of recurrence and mortality. Anti-angiogenesis drugs have been used for the therapy of HCC. However, anti-angiogenic drug resistance commonly occurs during HCC treatment. Thus, identification of a novel VEGFA regulator would be better understanding for HCC progression and anti-angiogenic therapy resistance. Ubiquitin specific protease 22 (USP22) as a deubiquitinating enzyme, participates in a variety of biological processes in numerous tumors. While the molecular mechanism underlying the effects of USP22 on angiogenesis is still needed to be clarified. Here, our results demonstrated that USP22 acts as a co-activator of VEGFA transcription. Importantly, USP22 is involved in maintenance of ZEB1 stability via its deubiquitinase activity. USP22 was recruited to ZEB1-binding elements on the promoter of VEGFA, thereby altering histone H2Bub levels, to enhance ZEB1-mediated VEGFA transcription. USP22 depletion decreased cell proliferation, migration, Vascular Mimicry (VM) formation, and angiogenesis. Furthermore, we provided the evidence to show that knockdown of USP22 inhibited HCC growth in tumor-bearing nude mice. In addition, the expression of USP22 is positively correlated with that of ZEB1 in clinical HCC samples. Our findings suggest that USP22 participates in the promotion of HCC progression, if not all, at least partially via up-regulation of VEGFA transcription, providing a novel therapeutic target for anti-angiogenic drug resistance in HCC.

Tuberous Sclerosis Complex With Multiple Organ Tumors: Case Report and Literature Review.

Pancreatic neuroendocrine neoplasms (PNEN) are tumors that originate from neuroendocrine cells. Only about 1% patients are related to mutation of tuberous sclerosis complex gene. Here, we reported a rare case with involvement of multiple organs and space-occupying lesions. Initially, the patient was thought to have metastasis of a pancreatic tumor. However, the patient was diagnosed as pancreatic neuroendocrine tumors, liver perivascular epithelioid tumors, splenic hamartoma, and renal angiomyolipoma by pathological examination after surgery. We performed genetic mutation detection to identify that tuberous sclerosis complex 2 gene presented with a heterozygous variant. Tuberous sclerosis often presents with widespread tumors, but it is less common to present with pancreatic neuroendocrine tumors and liver perivascular tumors as highlighted in the case. So we analyzed the relationship between TSC gene mutations and related tumors. And we also reviewed the current molecular mechanisms and treatments for tuberous sclerosis complex.

A randomized controlled trial to compare the efficacy of regenerated and non-regenerated oxidized cellulose gauze for the secondary treatment of local bleeding in patients undergoing hepatic resection.

PURPOSE: Oxidized cellulose is available in many forms, but manufactured using either a regenerated or non-regenerated process. In this study, we evaluated the effects of 2 different hemostatic agents for the treatment of local bleeding in patients undergoing hepatic resection. METHODS: This was a monocentric, parallel-group, randomized, and controlled clinical trial to compare oxidized regenerated cellulose gauze (ORCG) with oxidized non-regenerated cellulose gauze (ONRCG) in patients undergoing hepatectomy. The primary endpoint was the time to hemostasis at the target bleeding site. The secondary endpoints were the postoperative drainage volume on the first 2 days after surgery and the hospital stay. RESULTS: There was no significant difference between the ORCG and ONRCG groups in time to hemostasis from column analysis (238.8 ± 121.6 seconds vs. 193.7 ± 85.3 seconds, P = 0.068), and there were no differences in the rates of hemostatic success between the 2 groups at 120 seconds (18.4% vs. 24.3%; odds ratio [OR], 0.703; 95% confidence interval [CI], 0.231-2.136) and 300 seconds (71.1% vs. 89.2%; OR, 0.298; 95% CI, 0.085-1.041). However, the ONRCG group was superior to the ORCG group in hemostasis according to the survival analysis (log-rank test, P = 0.044). Moreover, there were also no significant differences between the 2 groups in postoperative drainage volume on the first 2 days (P = 0.436, P = 0.381) and hospital stay (P = 0.537, P = 0.200). CONCLUSION: ONRCG was not inferior to ORCG as a hemostatic agent in patients undergoing liver resection.

High Expression of LINC01268 is Positively Associated with Hepatocellular Carcinoma Progression via Regulating MAP3K7.

OBJECTIVE: As one of the most common neoplastic diseases, hepatocellular carcinoma (HCC) has a high morbidity and mortality, which seriously threatens human health and places a heavy burden on society and medical care. At present, effective early diagnosis, prognosis and treatment of HCC are limited. Altered gene expression patterns of lncRNA are associated with the occurrence, development and prognosis of various malignancies, including HCC. The aim of this study was to investigate the correlation between the expression of LINC01268 and HCC, and to elucidate the potential underlying molecular mechanism. METHODS: Expression level and localization of LINC01268 in human liver cancer cells and HCC tissues were investigated using RT-qPCR and fluorescent in situ hybridization (FISH), respectively. Correlation of expression levels of LINC01268 and MAP3K7 with differentiation and poor overall patient survival of HCC were analyzed using in house collected and publicly available HCC tissue data. RT-qPCR and Western blot were applied to inspect the effects of depletion and overexpression of LINC01268 on MAP3K7 expression. HCC cell proliferation and apoptosis were also investigated by simultaneous overexpression of LINC01268 and knockdown of MAP3K7, in order to delineate that MAP3K7 is a downstream effector of LINC01268. RESULTS: In this study, we identified that LINC01268 was highly expressed in HCC cell lines and tissues. High LINC01268 expression level was associated with lower HCC nodule number, moderate/poor differentiation and poor overall survival. Knockdown of LINC01268 inhibited the proliferation of HCC cells, which was enhanced by overexpression of LINC01268. Co-expression analysis implied an interaction between LINC01268 and MAP3K7. Similar to LINC01268, MAP3K7 was highly expressed in HCC cells, and positively correlated with moderate/poor differentiation as well as poor prognosis. Knockdown of LINC01268 in HCC cell lines led to reduction of MAP3K7 at both mRNA and protein levels. Phenotypic effects due to LINC01268 overexpression in HCC cells were reversed by knockdown of MAP3K7. CONCLUSION: Taken together, the abnormal high expression of LINC01268 is associated with HCC progression via regulating MAP3K7, suggesting LINC01268 as a novel marker for HCC prognosis and potentially a new therapeutic target.

The role of Transfer RNA-Derived Small RNAs (tsRNAs) in Digestive System Tumors.

Transfer RNA-derived small RNA(tsRNA) is a type of non-coding tRNA undergoing cleavage by specific nucleases such as Dicer. TsRNAs comprise of tRNA-derived fragments (tRFs) and tRNA halves (tiRNAs). Based on the splicing site within the tRNA, tRFs can be classified into tRF-1, tRF-2, tRF-3, tRF-5, and i-tRF. TiRNAs can be classified into 5'-tiRNA and 3'-tiRNA. Both tRFs and tiRNAs have important roles in carcinogenesis, especially cancer of digestive system. TRFs and tiRNAs can promote cell proliferation and cell cycle progression by regulating the expression of oncogenes, combining with RNA binding proteins such as Y-box binding protein 1 (YBX1) to prevent transcription. Despite many reviews on the basic biological function of tRFs and tiRNAs, few have described their correlation with tumors especially gastrointestinal tumor. This review focused on the relationship of tRFs and tiRNAs with the biological behavior, clinicopathological characteristics, diagnosis, treatment and prognosis of digestive system tumors, and would provide novel insights for the early detection and treatment of digestive system tumors.

ATXN7L3 positively regulates SMAD7 transcription in hepatocellular carcinoma with growth inhibitory function.

BACKGROUND: Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide, with unmet need for the pharmacological therapy. The functions of ATXN7L3 in HCC progression are not known. METHODS: RNA sequence, quantitative real-time PCR, and western blot were performed to detect gene expression. Chromatin immunoprecipitation was performed to detect possible mechanisms. Immunohistochemical stain was performed to examine the protein expression. Colony formation, cell growth curve and xenograft tumor experiments were performed to examine cell growth in vitro and in vivo. FINDINGS: ATXN7L3 functions as a coactivator for ERα-mediated transactivation in HCC cells, thereby contributing to enhanced SMAD7 transcription. ATXN7L3 is recruited to the promoter regions of SMAD7 gene, thereby regulating histone H2B ubiquitination level, to enhance the transcription of SMAD7. A series of genes regulated by ATXN7L3 were identified. Moreover, ATXN7L3 participates in suppression of tumor growth. In addition, ATXN7L3 is lower expressed in HCC samples, and the lower expression of ATXN7L3 positively correlates with poor clinical outcome in patients with HCC. INTERPRETATION: This study demonstrated that ATXN7L3 is a novel regulator of SMAD7 transcription, subsequently participating in inhibition of tumor growth in HCC, which provides an insight to support a previously unknown role of ATXN7L3 in HCC progression. FUND: This work was funded by 973 Program Grant from the Ministry of Science and Technology of China (2013CB945201), National Natural Science Foundation of China (31871286, 81872015, 31701102, 81702800, 81902889), Foundation for Special Professor of Liaoning Province, Natural Science Foundation of Liaoning Province (No.20180530072); China Postdoctoral Science Foundation (2019M651164).

Splicing factor PRPF6 upregulates oncogenic androgen receptor signaling pathway in hepatocellular carcinoma.

Androgen receptor (AR) signaling is considered to be crucial for the pathogenesis of hepatocellular carcinoma (HCC) with obvious sexual dimorphism. Pre-mRNA processing factor 6 (PRPF6) was identified as a coactivator of AR. However, the molecular mechanism underlying the modulation function of PRPF6 on AR-mediated transcriptional activity in HCC needs to be further clarified. In this study, we analyzed data from The Cancer Genome Atlas to show that PRPF6 is highly expressed in HCC. . Our data indicated that PRPF6 interacts with AR/AR splice variants (AR-Vs) and upregulates AR/AR splice variant 7-mediated transcriptional activity even without dihydrotestosterone treatment. We observed that AR is obviously induced by androgen treatment and is mainly expressed in the nucleus in HCC-derived cell lines. Moreover, overexpression of PRPF6 enhances AR expression accompanied with the increase of AR-Vs expression. We provided evidence that PRPF6 participates in upregulating AR self-transcription. PRPF6 facilitates the recruitment of AR to the androgen responsive element region of the AR gene. Finally, PRPF6 depletion inhibits cell proliferation in HCC cells and mouse xenografts. Taken together, our results suggest that PRPF6 as a splicing factor enhances AR self-transcription, thereby coactivating oncogenic AR/AR-Vs actions in HCC.

USP22 positively modulates ERα action via its deubiquitinase activity in breast cancer.

Estrogen receptor α (ERα) is the crucial factor in ERα-positive breast cancer progression. Endocrine therapies targeting ERα signaling is one of the widely used therapeutic strategies for breast cancer. However, a large number of the patients become refractory to therapy. Abnormal expression of ERα co-regulator facilitates breast cancer development and tendency of endocrine resistance. Thus, it is necessary to discover the novel co-regulators modulating ERα action. Here, we demonstrate that histone deubiquitinase USP22 is highly expressed in breast cancer samples compared with that in the benign tissue, and high expression of USP22 was significantly associated with poorer overall survival in BCa samples. Moreover, USP22 associates with ERα to be involved in maintenance of ERα stability. USP22 enhances ERα-induced transactivation. We further provide the evidence that USP22 is recruited together with ERα to cis-regulatory elements of ERα target gene. USP22 promotes cell growth even under hypoxia condition and with the treatment of ERα antagonist in breast cancer cells. Importantly, the deubiquitination activity of USP22 is required for its functions on maintenance of ERα stability, thereby enhancing ERα action and conferring endocrine resistance in breast cancer.

microRNA-519d Induces Autophagy and Apoptosis of Human Hepatocellular Carcinoma Cells Through Activation of the AMPK Signaling Pathway via Rab10.

BACKGROUND AND AIM: Hepatocellular carcinoma (HCC) is a type of cancer with high mortality rates. The overexpression of microRNA-519d (miR-519d) has been explored in different types of cancers, which could significantly help suppress cancer development. This study aimed to investigate the interaction of miR-519d with its target gene, Rab10, as well as its effects on cell proliferation and autophagy in HCC cells through modulation of the AMPK signaling pathway. METHODS: Microarray analysis was used to analyze the differentially expressed genes in HCC, and the target genes of the screened-out miRNA were predicted and verified. The expression of miR-519d and Rab10, AMPK signaling pathway-related proteins, apoptosis- and autophagy-related proteins was determined by RT-qPCR and Western blot analysis in HCC tissues and cell lines. Lastly, the effects of miR-519d and Rab10 in HCC cell proliferation, apoptosis, and mouse tumour xenograft in vivo were examined through gain- and loss-of-function experiments. RESULTS: MiR-519d was down-regulated and Rab10 was upregulated in HCC tissues and cell lines. Overexpression of miR-519d decreased the expression of Rab10, mTOR, and Bcl-2, but increased the expression of Bax, Beclin1, Atg5, and p53. Upregulated miR-519d and downregulated Rab10 expression suppressed cell proliferation and induced cell apoptosis and autophagy in HCC cells. Finally, upregulation of miR-519d inhibited tumour growth in vivo. CONCLUSION: The result obtained in this study indicates that up-regulation of miR-519d inhibits proliferation and promotes apoptosis and autophagy of HCC cells through activation of the AMPK signaling pathway via downregulating Rab10, which provides a potential target for the treatment of HCC.

Pedunculated Hepatocellular Carcinoma Mimicking Right Adrenal Tumor on FDG PET/CT.

Pedunculated hepatocellular carcinoma is an unusual form of hepatocellular carcinoma protruding from the liver with or without a pedicle. We present a case of pedunculated hepatocellular carcinoma misdiagnosed as right adrenal tumor on MRI and FDG PET/CT. Intraoperative exploration revealed the mass was attached to the liver, but the right adrenal gland was intact. Laparoscopic biopsy revealed poorly differentiated hepatocellular carcinoma. This case indicates it may be difficult to diagnose pedunculated hepatocellular carcinoma because it is hard to define its origin on imaging. Elevated alpha-fetoprotein level and a history of viral hepatitis may be helpful for the diagnosis.

FDG PET/CT in 2 Cases of Hepatic Pseudolymphoma.

Hepatic pseudolymphoma, also known as reactive lymphoid hyperplasia or nodular lymphoid hyperplasia, is a rare benign lymphoproliferative lesion. Preoperative diagnosis of hepatic pseudolymphoma is challenging. We present 2 cases of hepatic pseudolymphoma with focal intense FDG uptake on FDG PET/CT mimicking malignancy. These 2 cases suggest that hepatic pseudolymphoma should be considered as a rare differential diagnosis in patients with focal hypermetabolic hepatic lesion.

RNF8 identified as a co-activator of estrogen receptor α promotes cell growth in breast cancer.

The ring finger protein 8 (RNF8), a key component of protein complex crucial for DNA-damage response, consists of a forkhead-associated (FHA) domain and a really interesting new gene (RING) domain that enables it to function as an E3 ubiquitin ligase. However, the biological functions of RNF8 in estrogen receptor α (ERα)-positive breast cancer and underlying mechanisms have not been fully defined. Here, we have explored RNF8 as an associated partner of ERα in breast cancer cells, and co-activates ERα-mediated transactivation. Accordingly, RNF8 depletion inhibits the expression of endogenous ERα target genes. Interestingly, our results have demonstrated that RNF8 increases ERα stability at least partially if not all via triggering ERα monoubiquitination. RNF8 functionally promotes breast cancer cell proliferation. RNF8 is highly expressed in clinical breast cancer samples and the expression of RNF8 positively correlates with that of ERα. Up-regulation of ERα-induced transactivation by RNF8 might contribute to the promotion of breast cancer progression by allowing enhancement of ERα target gene expression. Our study describes RNF8 as a co-activator of ERα increases ERα stability via post-transcriptional pathway, and provides a new insight into mechanisms for RNF8 to promote cell growth of ERα-positive breast cancer.

BAP18 coactivates androgen receptor action and promotes prostate cancer progression.

BPTF associated protein of 18 kDa (BAP18) has been reported as a component of MLL1-WDR5 complex. However, BAP18 is an uncharacterized protein. The detailed biological functions of BAP18 and underlying mechanisms have not been defined. Androgen receptor (AR), a member of transcription factor, plays an essential role in prostate cancer (PCa) and castration-resistant prostate cancer (CRPC) progression. Here, we demonstrate that BAP18 is identified as a coactivator of AR in Drosophilar experimental system and mammalian cells. BAP18 facilitates the recruitment of MLL1 subcomplex and AR to androgen-response element (ARE) of AR target genes, subsequently increasing histone H3K4 trimethylation and H4K16 acetylation. Knockdown of BAP18 attenuates cell growth and proliferation of PCa cells. Moreover, BAP18 depletion results in inhibition of xenograft tumor growth in mice even under androgen-depletion conditions. In addition, our data show that BAP18 expression in clinical PCa samples is higher than that in benign prostatic hyperplasia (BPH). Our data suggest that BAP18 as an epigenetic modifier regulates AR-induced transactivation and the function of BAP18 might be targeted in human PCa to promote tumor growth and progression to castration-resistance.

SNF5 is Involved in Suppression of Hepatocellular Carcinoma Progression via TGF-Beta 1 Signaling.

SNF5 (SMARCB1/INI1/BAF47), a core subunit of SWI/SNF complex, has been reported to modulate cell proliferation and apoptosis. Genetic evidence has suggested that SNF5 participates in tumor suppression. However, the detailed biological function and underlying mechanisms of SNF5 in hepatocellular carcinoma (HCC) progression remain unclear. Here, SNF5 expression reduction in HCC tissues compared with the adjacent non-cancerous tissues has been demonstrated. Importantly, the results showed that reduced SNF5 expression has a strong correlation with worse overall survival of HCC patients. The data demonstrated that knockdown of SNF5 significantly promoted cell growth and migration in Hep3B and HCCLM3 cell lines. Interestingly, it was found that SNF5 suppressed transforming growth factor-ß1 (TGF-ß1) expression, and SNF5 mRNA expression was negatively correlated with TGF-ß1 in HCC tissues. Furthermore, depletion of SNF5 attenuated the sensitivity of HCC cells to sorafenib. Thus, the data suggested that SNF5 may participate in HCC suppression, and reduced expression of SNF5 correlates with the poor differentiation and prognosis of HCC, indicating that SNF5 might be an important prognostic biomarker and promising therapeutic target for HCC. Anat Rec, 299:869-877, 2016. © 2016 Wiley Periodicals, Inc.

MDC1 Enhances Estrogen Receptor-mediated Transactivation and Contributes to Breast Cancer Suppression.

Estrogen receptor α (ERα) is a key transcriptional factor in the proliferation and differentiation in mammary epithelia and has been determined to be an important predictor of breast cancer prognosis and therapeutic target. Meanwhile, diverse transcriptional co-regulators of ERα play crucial and complicated roles in breast cancer progression. Mediator of DNA damage checkpoint 1 (MDC1) has been identified as a critical upstream mediator in the cellular response to DNA damage, however, some non-DNA damage responsive functions of MDC1 haven't been fully defined. In this study, we have identified MDC1 as a co-activator of ERα in breast cancer cells and demonstrated that MDC1 associates with ERα. MDC1 was also recruited to estrogen response element (ERE) of ERα target gene. Knockdown of MDC1 reduced the transcription of the endogenous ERα target genes, including p21. MDC1 depletion led to the promotion of breast cancer progression, and the expression of MDC1 is lower in breast cancer. Taken together, these results suggested that MDC1 was involved in the enhancement of ERα-mediated transactivation in breast cancer cells. This positive regulation by MDC1 might contribute to the suppression of breast cancer progression by acting as a barrier of positive to negative ERα function transformation.

CD105 promotes hepatocarcinoma cell invasion and metastasis through VEGF.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related morbidity and mortality. Tumor neovascularization is necessarily required for tumor progression and metastasis. CD105 and vascular endothelial growth factor (VEGF) have separately been identified as important contributors to angiogenesis; however, it is unclear if these factors interact to promote the progression of HCC. The goal of this study was to determine the interaction between CD105 and VEGF in HCC, using HCC tissue samples and the human HCC cell line SMMC-7721. In a survey of 89 HCC tumor samples, we determined that CD105 and VEGF expressions were positively correlated with each other and expressed at a higher level in tumor cells. Furthermore, the expression of CD105 was closely related to the tumor-node-metastasis (TNM) staging of HCC, degree of tumor differentiation, portal vein invasion, and lymph node metastasis (P < 0.05). Next, we used a lentiviral system to stably overexpress CD105 in SMMC-7721 cells, which was confirmed at the messenger RNA (mRNA) and protein level. We observed that VEGF expression was increased in these cells, as was cell motility and migration, as assessed using a wound healing assay and Transwell chamber system, respectively. Using VEGF small interfering RNA (siRNA), we also demonstrated that elevated VEGF expression is required to promote increased cell motility and migration in CD105-overexpressing cells. In conclusion, we interpret our data to prove that CD105 promotes the invasion and metastases of liver cancer cells by increasing VEGF expression. These results provide a new theoretical and experimental basis for the treatment of liver cancer.

Pri-miR-34b/c rs4938723 TC heterozygote is associated with increased cancer risks: evidence from published data.

The promoter region of the microRNA pri-miR-34b/c has a potentially functional polymorphism, rs4938723, located in a typical CpG island. Studies of the association between pri-miR-34b/c rs4938723 polymorphism and risks of various cancers have had inconsistent results. We therefore conducted a meta-analysis of nine studies that included 6,036 cancer patients and 7,490 controls to address this association. Overall, this meta-analysis showed the pri-miR-34b/c rs4938723 TC heterozygote to be significantly associated with increased risk of overall cancers compared with the wild-type TT genotype (P = 0.010, odds ratio (OR) = 1.10, 95 % confidence interval (CI) 1.02-1.18). In stratified analysis, the TC heterozygote was significantly associated with increased cancers risks in digestive tract cancers, in hepatocellular cancer, in Asian population and in the large-sample subgroup. The CC genotypes of rs4938723 were also associated with increased hepatocellular cancer risk but associated with decreased colorectal cancer risk in the stratification analysis by a single cancer type. Thus our meta-analysis suggests that the pri-miR-34b/c rs4938723 TC heterozygote contributes to increased overall cancer risks, as well as shown in digestive tract cancers, in hepatocellular cancer, in Asian population and in the large-sample subgroup. This rs4938723 SNP showed an opposite tendency orientation between the hepatocellular cancer and colorectal cancer risks. Large-sample studies are needed to verify our findings.