Background Cholangiocarcinoma (CCA) is a biliary epithelial malignant tumor with an increasing incidence worldwide. Therefore, further understanding of the molecular mechanisms of CCA progression is required to identify new therapeutic targets. Methods The expression of RPL35A in CCA and para-carcinoma tissues was detected by immunohistochemical staining. IP-MS combined with Co-IP identified downstream proteins regulated by RPL35A. Western blot and Co-IP of CHX or MG-132 treated CCA cells were used to verify the regulation of HSPA8 protein by RPL35A. Cell experiments and subcutaneous tumorigenesis experiments in nude mice were performed to evaluate the effects of RPL35A and HSPA8 on the proliferation, apoptosis, cell cycle, migration of CCA cells and tumor growth in vivo. Results RPL35A was significantly upregulated in CCA tissues and cells. RPL35A knockdown inhibited the proliferation and migration of HCCC-9810 and HUCCT1 cells, induced apoptosis, and arrested the cell cycle in G1 phase. HSPA8 was a downstream protein of RPL35A and overexpressed in CCA. RPL35A knockdown impaired HSPA8 protein stability and increased HSPA8 protein ubiquitination levels. RPL35A overexpression promoted CCA cell proliferation and migration. HSPA8 knockdown inhibited CCA cell proliferation and migration, and reversed the promoting effect of RPL35A. Furthermore, RPL35A promoted tumor growth in vivo. In contrast, HSPA8 knockdown suppressed tumor growth, while was able to restore the effects of RPL35A overexpression. Conclusion RPL35A was upregulated in CCA tissues and promoted the progression of CCA by mediating HSPA8 ubiquitination.

BackgroundThe heterogeneity of the tumor microenvironment significantly influences the prognosis of hepatocellular carcinoma (HCC) patients, with cell communication through ligand-receptor complexes playing a central role.MethodsWe conducted single-cell transcriptomic analysis on ten HCC tissues to identify ligand-receptor genes involved in malignant HCC cell communication using CellChat. Leveraging RNA-Seq data from the TCGA Liver Cancer (TCGA-LIHC) and Liver Cancer - RIKEN, JP (LIRI-JP) cohorts, we employed Cox regression analysis to screen for prognosis-related genes. Prognostic risk models were constructed through unsupervised clustering and differential gene expression analysis. Subsequently, a co-culture system involving tumor cells and macrophages was established. A series of experiments, including Transwell assays, immunofluorescence staining, immunoprecipitation, flow cytometry, and immunohistochemistry, were conducted to elucidate the mechanism through which HCC cells recruit macrophages via the CCL16-CCR1 axis.ResultsSingle-cell analysis unveiled significant interactions between malignant HCC cells and macrophages, identifying 76 related ligand-receptor genes. Patients were classified into three subtypes based on the expression patterns of eight prognosis-related ligand-receptor genes. The subtype with the worst prognosis exhibited reduced infiltration of T cell-related immune cells, downregulation of immune checkpoint genes, and increased M2-like tumor-associated macrophage scores. In vitro experiments confirmed the pivotal role of the CCL16-CCR1 axis in the recruitment and M2 polarization of tumor-associated macrophages. Clinical samples demonstrated a significant association between CCL16 protein expression levels and advanced stage, lymph node metastasis, and distant metastasis. Immunohistochemistry and immunofluorescence staining further confirmed the correlation between CCL16 and CCR1, CD68, and CD206, as well as CD68+CCR1+ macrophage infiltration.ConclusionsOur study identified molecular subtypes, a prognostic model, and immune microenvironment features based on ligand-receptor interactions in malignant HCC cell communication. Moreover, we revealed the pro-tumorigenic role of HCC cells in recruiting M2-like tumor-associated macrophages through the CCL16-CCR1 axis.

The histone acetyltransferase MOF (KAT8) is mainly involved in the acetylation of histone H4 at lysine 16 (H4K16) and some non-histone proteins. The MOF expression level is significantly reduced in many cancers, however the biological function of MOF and its underlying mechanism are still elusive in hepatocellular carcinoma (HCC). Estrogen receptor α (ERα) has been considered as a tumor suppressor in HCC. Here, we demonstrated that MOF expression is significantly reduced in HCC samples, and is positively correlated with that of ERα. MOF interacts with ERα, and participates in acetylation of ERα at K266, K268, K299, thereby inhibiting ERα ubiquitination to maintain the stability of ERα. In addition, MOF participates in the upregulation of ERα-mediated transactivation. Depletion of MOF significantly promotes cell growth, migration, and invasion in HCC cell lines. Taken together, our results provide new insights to understand the mechanism underlying the modulation function of MOF on ERα action in HCC, suggesting that MOF might be a potential therapeutic target for HCC.

1Department of Cell Biology, Key laboratory of Cell Biology, Ministry of Public Health, and Key laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, Liaoning 110122, China, 2Department of General Surgery, the First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, China and 3School of Computer Science and Engineering, Northeastern University, Shenyang, Liaoning 110004, China

Androgen receptor (AR) and its variants play vital roles in development and progression of prostate cancer. To clarify the mechanisms involved in the enhancement of their actions would be crucial for understanding the process in prostate cancer and castration-resistant prostate cancer transformation. Here, we provided the evidence to show that pre-mRNA processing factor 6 (PRPF6) acts as a key regulator for action of both AR full length (AR-FL) and AR variant 7 (AR-V7), thereby participating in the enhancement of AR-FL and AR-V7-induced transactivation in prostate cancer. In addition, PRPF6 is recruited to cis-regulatory elements in AR target genes and associates with JMJD1A to enhance AR-induced transactivation. PRPF6 also promotes expression of AR-FL and AR-V7. Moreover, PRPF6 depletion reduces tumor growth in prostate cancer-derived cell lines and results in significant suppression of xenograft tumors even under castration condition in mouse model. Furthermore, PRPF6 is obviously highly expressed in human prostate cancer samples. Collectively, our results suggest PRPF6 is involved in enhancement of oncogenic AR signaling, which support a previously unknown role of PRPF6 during progression of prostate cancer and castration-resistant prostate cancers.

目的:构建编码ubiquitin specific peptidase 22(USP22)截短蛋白的表达质粒,探索USP22在肝细胞肝癌(hepatocellular carcinoma,HCC)中的作用及其分子机制,并初步解析USP22在HCC细胞系中对细胞增殖及索拉菲尼作用的影响.方法:设计合成针对于人源 USP22 截短质粒序列的引物,通过 PCR的方法以含有USP22全长蛋白编码序列的表达载体作为模板,扩增目的片段,再用限制性内切酶EcoRⅠ和XhoⅠ进行双酶切,连接转化后,将构建好的质粒进行酶切鉴定及测序,证明USP22 截短质粒构建成功.将构建好的USP22全长及截短表达质粒转染到HCC细胞系HCC－LM3中,分别进行Western blot和confocal实验检测USP22全长及截短质粒在HCC－LM3细胞中的表达及定位.生物学功能方面,利用MTS法检测USP22全长对HCC细胞增殖及索拉菲尼作用的影响.结果:成功构建了USP22 截短表达质粒,并在HCC细胞系HCC－LM3 中验证了其蛋白表达;USP22全长及所构建的截短质粒编码蛋白在HCC－LM3 中定位于细胞核;此外,生物学功能实验证实USP22促进HCC－LM3细胞增殖,并削弱了索拉菲尼对HCC－LM3细胞生长的抑制作用.结论:在HCC－LM3细胞中,USP22及其截短质粒编码蛋白均定位于细胞核;USP22 促进HCC细胞增殖,且可能参与在HCC治疗中的索拉菲尼耐受进程.

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).

Estrogen receptor alpha (ER alpha) signaling pathway is essential for ER alpha-positive breast cancer progression and endocrine therapy resistance. Bromodomain PHD Finger Transcription Factor (BPTF) associated protein of 18kDa (BAP18) has been recognized as a crucial H3K4me3 reader. However, the whole genomic occupation of BAP18 and its biological function in breast cancer is still elusive. Here, we found that higher expression of BAP18 in ER alpha-positive breast cancer is positively correlated with poor prognosis. ChIP-seq analysis further demonstrated that the half estrogen response elements (EREs) and the CCCTC binding factor (CTCF) binding sites are the significant enrichment sites found in estrogen-induced BAP18 binding sites. Also, we provide the evidence to demonstrate that BAP18 as a novel co-activator of ER alpha is required for the recruitment of COMPASS-like core subunits to the cis-regulatory element of ER alpha target genes in breast cancer cells. BAP18 is recruited to the promoter regions of estrogen-induced genes, accompanied with the enrichment of the lysine 4-trimethylated histone H3 tail (H3K4me3) in the presence of E2. Furthermore, BAP18 promotes cell growth and associates the sensitivity of antiestrogen in ER alpha-positive breast cancer. Our data suggest that BAP18 facilitates the association between ER alpha and COMPASS-like core subunits, which might be an essential epigenetic therapeutic target for 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.

Absent, small or homeotic 2-like protein (ASH2L) is a core component of a multimeric histone methyltransferase complex that is involved in the maintenance of active transcription, participating in several cancers, however the biological function and molecular mechanism of ASH2L in endometrial cancer (ECa) are largely unknown. Endometrial cancer is a common malignant tumor in women and the incidence of this cancer is on the rise. Estrogen-ERα signaling, as an oncogenic pathway, plays a crucial role in endometrial carcinogenesis. Therefore, further exploration of the molecular mechanisms around ERα-mediated gene transcription in ECa would be helpful to the understanding of tumor development and to finding a new therapeutic target for ECa. Here, our study demonstrated that ASH2L was highly expressed in ECa samples, and higher expression of ASH2L was positively correlated with a poor prognosis. Moreover, we identified that ASH2L associated with ERα and that knockdown of ASH2L resulted in decreased expression of a subset of the estrogen-induced target genes, including paired box 2 (PAX2), an oncogenic gene in ECa. ASH2L was recruited to cis-regulatory elements in PAX2, thereby altering histone H3K4me3 and H3K27me3 levels, to enhance ERα-mediated transactivation. Finally, depletion of ASH2L suppressed endometrial cancer cell proliferation and migration. Our findings suggest that ASH2L participates in the promotion of ECa progression, if not totally at least partially, via upregulation of PAX2 transcription.

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.

Background: Estrogen-ERα signaling is an oncogenic pathway plays a crucial role in endometrial carcinogenesis. However, modulation of ERα action in Endometrial cancer (ECa) remains to be elusive. Absent, small or homeotic 2-like protein (ASH2L) is a core component of multimeric histone methyltransferase complex, which is involved in maintenance the active chromatin states. What is the function of ASH2L on modulation of E2-ERα induced transactivation in ECa needs to be further understood.Methods: Immunoprecipitation, Immunofluorescence assay, luciferase assay, quantitative RT-PCR, and western blot were performed to investigate how ASH2L regulates the transcriptional activity of ERα. ChIP assay was performed to determine the recruitment of ASH2L to cis-regulatory elements. Lentiviral infection, colony formation, transwell experiments, and mice xenograft experiments were performed to evaluate the function of ASH2L on cell growth and migration.Findings: Our study demonstrated that ASH2L was highly expressed in ECa samples, and the higher expression of ASH2L is positively correlated with the poor prognosis. ASH2L associates with ERα and upregulates ERα-induced transactivation in ECa cells. ASH2L is recruited to cis -regulatory elements at ERα regulated gene, thereby modulating histone H3K4me3 and H3K27me3 levels, to maintain the active transcription. ASH2L depletion suppresses cell growth and migration in ECa.Interpretation: Our findings suggest that ASH2L associates with ERα to be involved in regulation of ERα-induced transactivation. ASH2L participates in promotion of ECa progression.Funding Statement: This study was supported by National Natural Science Foundation of China [31871286 for Yue Zhao, 81872015 for Chunyu Wang, 31701102 for Shengli Wang, 81702800 for Renlong Zou, 81502438 for Tingting Zhou, 81902889 for Wensu Liu].Declaration of Interests: The authors declare no conflict of interests.Ethics Approval Statement: All procedures of animal experiments have been carried out in compliance with ethical regulations approved by the Animal Ethics Committee of China Medical University.This study was approved by the Ethics Committee of the Medical Faculty of the China Medical University.

Background: As a reader of histone H3K4me3, BPTF associated protein of 18 kDa (BAP18) is involved in modulation of androgen receptor action in prostate cancer. However, the function of BAP18 on oral squamous cell carcinoma (OSCC) and its molecular mechanism remains to be elusive. Methods: OSCC-derived cell lines carrying silenced BAP18 were established by Lentiviral infection. Quantitative PCR (qPCR), western blot, and ChIP assay were performed to detect gene transcription regulation and the possible mechanism. Colony formation, cell growth curve and xenograft tumor experiments were performed to examine cell growth and proliferation. Findings: Our study demonstrated that BAP18 was highly expressed in OSCC samples compared with that in benign. BAP18 depletion obviously influenced the expression of a series of genes, including cell cycle-related genes. We thus provided the evidence to demonstrate that BAP18 depletion significantly decreases CCND1 and CCND2 (CCND1/2) transcription. In addition, BAP18 is recruited to the promoter regions of CCND1/2, thereby facilitating the recruitment of the core subunits of MLL1 complex to the same regions, to increase histone H3K4me3 levels. Furthermore, BAP18 depletion delayed G1-S phase transition and inhibited cell growth in OSCC-derived cell lines. Interpretation: This study suggests that BAP18 is involved in modulation of CCND1/2 transcription and promotes OSCC progression. BAP18 could be a potential target for OSCC treatment and diagnosis. Fund: This work was funded by National Natural Science Foundation of China (31871286, 81872015, 31701102, 81702800, 81902889), Foundation for Special Professor of Liaoning Province, and Supported project for young technological innovation-talents in Shenyang (No. RC170541). (c) 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Background hIAPP is formed in islet β cells, misfolded hIAPP results in the deposition inside the β-cells and shows a damage to the β-cells. The mechanism of hIAPP deposition after islet transplantation is mainly focused on non-immune factors and there is no report whether calcineurin inhibitors will increase hIAPP deposition after islet transplantation. Method The stably expressing hIAPP INS-1(hIAPP-INS1) cells was established. The hIAPP-INS1 cells and its control were cultured with different concentrations of tacrolimus and cyclosporine A, respectively. The hIAPP mRNA expression was detected by quantitative RT-PCR (qRT-PCR). The deposition of hIAPP was stained by thioflavin S using fluorescent microscope and chemiluminescence detector. The proliferation activity was test by MTS. The GSIS (glucose stimulated insulin secretion) was measured by ELISA. The expression of JAK2, Foxa2 and hIAPP was detected when the cells were treated with tacrolimus. The change of hIAPP and the GSIS was investigated when the cells were then cultured with resveratrol. Results The expression of hIAPP was obviously upregulated in hIAPP-INS1 cells. Compared with control, hIAPP-INS1 cells had a significant decrease in GSIS. There was a significant difference on proliferation activity, hIAPP expression and GSIS with the increase concentrations of tacrolimus in hIAPP-INS1 cells (P <0.05). However, there was no obvious difference on proliferation activity, hIAPP expression and GSIS with the increase concentrations of cyclosporine A in hIAPP-INS1 cells. In addition, tacrolimus stimulated Foxa2 expression to promote hIAPP deposition and resveratrol could degrade the deposition of hIAPP to protect hIAPP-INS1 cells. Conclusion hIAPP impaired GSIS in hIAPP-INS1 cells. Compared with cyclosporine A, tacrolimus significantly induced hIAPP deposition, inhibited hIAPP-INS1 cell proliferation activity and impaired GSIS in hIAPP-INS1 cells. Tacrolimus increased the deposition of hIAPP through the JAK2/Foxa2/hIAPP signaling pathway and resveratrol protects against tacrolimus induced hIAPP deposition in hIAPP-INS1 cells.

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.

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-β1 (TGF-β1) expression, and SNF5 mRNA expression was negatively correlated with TGF-β1 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.

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.