Search

Background miR-196b-5p expression is deregulated in many malignant tumors. Although miR-196b-5p has been implicated in the malignant transformation of colorectal cancer, its role in this specific type of cancer has not been fully explored. Thus, the present study was aimed to examine the cellular function of miR-196b-5p and its role in malignant biological behavior in colorectal cancer. Methods miR-196b-5p expression was measured in colorectal cancer tissues and cell lines using quantitative real-time PCR. Cell counting kit-8 (CCK-8) assay and Transwell assay were used to detect proliferation, migration, and invasion in cell lines, whereas flow cytometry was applied to study apoptosis. Western blot analysis was performed to measure the protein levels. Dual luciferase reporter assay was used to investigate the interaction between miR-196b-5p and ING5. Tumor formation was evaluated in mice. Results MiR-196b-5p was abundantly expressed in colorectal cancer tissues and cell lines, whereas ING5 was expressed at low levels. MiR-196b-5p was successfully overexpressed or knocked down in colorectal cancer cells. We found that miR-196b-5p overexpression significantly accelerated the proliferation, cell cycle, migration and invasion, while inhibited cell apoptosis in colorectal cancer cells. However, miR-196b-5p inhibitor showed the opposite effects. Moreover, ING5 overexpression or knockdown was successfully performed in colorectal cancer cells. ING5 overexpression suppressed proliferation, migration, invasion, the phosphorylation of PI3K, Akt as well as MEK, and promoted cell apoptosis, which could be reversed by ING5 knockdown. Additionally, ING5 was identified as a target of miR-196b-5p through bioinformatics analysis and a luciferase activity assay. Furthermore, ING5 knockdown could attenuate the decrease in proliferation, migration, invasion, and the protein levels of p-PI3K, p-Akt, and p-MEK, which were induced by miRNA-196b-5p inhibitor. Besides, miR-196b-5p knockdown inhibited tumor growth, whereas ING5 knockdown elevated it in vivo. Conclusions In conclusion, miR-196b-5p promotes cell proliferation, migration, invasion, and inhibits apoptosis in colorectal cancer by targeting ING5.

Aims: Lysine acetyltransferase 6B (KAT6B), is a histone acetyltransferase implicated to have a role in tumor suppression. However, the relationship between KAT6B and hepatocellular carcinoma (HCC) is unclear. The purpose of this study was to detect the expression of KAT6B in HCC tissues and analyze its connection with the clinicopathological features of HCC. Methods: First, we performed immunohistochemical staining on 250 HCC tissues and 222 non-tumor liver tissues to examine the expression of KAT6B.Then the relation between KAT6B expression and clinicopathological parameters was analyzed by chi-square test, and the overall survival analysis was conducted by Kaplan-Meier survival method. In addition, based on the Oncomine expression array online and the UALCAN database, we compared KAT6B expression differences between normal liver tissues and HCC tissues more broadly. Results: Compared with normal tissues, KAT6B expression was significantly lower in HCC tissues. Low KAT6B expression was found to be related to gender, AFP level, and tumor size. According to the online database, KAT6B expression was found to be decreased in HCC tissues and high in normal tissues. Conclusions: Lower expression of KAT6B is associated with poor prognosis of HCC, and KAT6B may be a potential tumor suppressor in liver cancer.

The INhibitor of Growth (ING) family of tumor suppressors regulates the transcriptional state of chromatin by recruiting remodeling complexes to sites with histone H3 trimethylated at lysine 4 (H3K4me3). This modification is recognized by the plant homeodomain (PHD) present at the C-terminus of the five ING proteins. ING5 facilitates histone H3 acetylation by the HBO1 complex, and also H4 acetylation by the MOZ/MORF complex. We show that ING5 forms homodimers through its N-terminal domain, which folds independently into an elongated coiled-coil structure. The central region of ING5, which contains the nuclear localization sequence, is flexible and disordered, but it binds dsDNA with micromolar affinity. NMR analysis of the full-length protein reveals that the two PHD fingers of the dimer are chemically equivalent and independent of the rest of the molecule, and they bind H3K4me3 in the same way as the isolated PHD. We have observed that ING5 can form heterodimers with the highly homologous ING4, and that two of three primary tumor-associated mutants in the N-terminal domain strongly destabilize the coiled-coil structure. They also affect cell proliferation and cell cycle phase distribution, suggesting a driver role in cancer progression., This work was supported by grant CTQ2017-83810-R (MINECO/FEDER/UE) to F.J.B., SAF2015-65690P to I.P., SAF2017-84092-R and SAF2014-51966-R to R.K., and SAF2017-84934-R to M.V. G.O. acknowledges a Formación de Personal Investigador Fellowship from MINECO (BES-2012-052851). We also thank MINECO for the Severo Ochoa Excellence Accreditation (SEV-2016-0644).

Background ING5 is the last member of the Inhibitor of Growth (ING) candidate tumor suppressor family that has been implicated in multiple cellular functions, including cell cycle regulation, apoptosis, and chromatin remodeling. Our previous study showed that ING5 overexpression inhibits lung cancer aggressiveness and epithelial-mesenchymal transition (EMT), with unknown mechanisms. Methods Western blotting was used to detect total and phosphorylated levels of β-catenin and EMT-related proteins. Immunofluorescent staining was used to observe E-cadherin expression. Proliferation and colony formation, wound healing, and Transwell migration and invasion assays were performed to study the proliferative and invasive abilities of cancer cells. Results ING5 overexpression promotes phosphorylation of β-catenin at Ser33/37, leading to a decreased β-catenin protein level. Small hairpin RNA-mediated ING5 knockdown significantly increased the β-catenin level and inhibited phosphorylation of β-catenin S33/37. Treatment with the WNT/β-catenin inhibitor XAV939 inhibited ING5-knockdown promoted proliferation, colony formation, migration, and invasion of lung cancer A549 cells, with increased phosphorylation of β-catenin S33/37 and a decreased β-catenin level. XAV939 also impaired ING5-knockdown-induced EMT, as indicated by upregulated expression of the EMT marker E-cadherin, an epithelial marker; and decreased expression of N-cadherin, a mesenchymal marker, and EMT-related transcription factors, including Snail, Slug, Twist, and Smad3. Furthermore, XAV939 could inhibit the activation of both IL-6/STAT3 and PI3K/Akt signaling pathways. Conclusion ING5 inhibits lung cancer invasion and EMT by inhibiting the WNT/β-catenin pathway.

Background Cisplatin resistance is a major challenge for advanced head and neck cancer (HNC). Understanding the underlying mechanisms and developing effective strategies against cisplatin resistance are highly desired in the clinic. However, how tumor stroma modulates HNC growth and chemoresistance is unclear. Results We show that cancer-associated fibroblasts (CAFs) are intrinsically resistant to cisplatin and have an active role in regulating HNC cell survival and proliferation by delivering functional miR-196a from CAFs to tumor cells via exosomes. Exosomal miR-196a then binds novel targets, CDKN1B and ING5, to endow HNC cells with cisplatin resistance. Exosome or exosomal miR-196a depletion from CAFs functionally restored HNC cisplatin sensitivity. Importantly, we found that miR-196a packaging into CAF-derived exosomes might be mediated by heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1). Moreover, we also found that high levels of plasma exosomal miR-196a are clinically correlated with poor overall survival and chemoresistance. Conclusions The present study finds that CAF-derived exosomal miR-196a confers cisplatin resistance in HNC by targeting CDKN1B and ING5, indicating miR-196a may serve as a promising predictor of and potential therapeutic target for cisplatin resistance in HNC. Electronic supplementary material The online version of this article (10.1186/s13059-018-1604-0) contains supplementary material, which is available to authorized users.

Background Pulmonary arterial hypertension (PAH) is often characterized by cell proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs). LncRNA cancer susceptibility candidate 2 (CASC2) has been revealed to be involved in PASMC injury in hypoxia-induced pulmonary hypertension. However, the exact molecular mechanisms whereby CASC2 regulates PASMC proliferation and migration are still incompletely understood. Methods The expression levels of CASC2, miR-222 and inhibitor of growth 5 (ING5) were measured using quantitative real-time polymerase chain reaction (qRT-PCR) or western blot, respectively. Cell proliferation was analyzed by Cell Counting Kit-8 (CCK-8) assay. Wound healing assay was used to analyze cell migration ability. The relationship between miR-222 and CASC2 or ING5 was confirmed using bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation assay. Results CASC2 was down-regulated in hypoxia-induced PASMCs in a dose- and time-dependent manner. Functional experiments showed that CASC2 overexpression could reverse hypoxia-induced proliferation and migration of PASMCs. Bioinformatics analysis indicated that CASC2 acted as a competing endogenous RNA of miR-222, thereby regulating the expression of ING5, the downstream target of miR-222, in PASMCs. In addition, rescue assay suggested that the inhibition mediated by CASC2 of hypoxia-induced PASMC proliferation and migration could be attenuated by miR-222 inhibition or ING5 overexpression. Conclusion CASC2 attenuated hypoxia-induced PASMC proliferation and migration by regulating the miR-222/ING5 axis to prevent vascular remodeling and the development of PAH, providing a novel insight and therapeutic strategy for hypoxia-induced PAH.

Here, we found that ING5 overexpression suppressed cell viability, glucose metabolism, migration, invasion and epithelial-mesenchymal transition, and induced cell arrest, apoptosis, senescence, autophagy and fat accumulation in ovarian cancer cells. ING5-mediated chemoresistance was positively linked to apoptotic resistance and chemoresistance-related gene expression. ING5 overexpression suppressed tumor growth of ovarian cancer by decreasing proliferation, and inducing apoptosis and autophagy. ING5 mRNA level was lower in ovarian cancer than normal ovary, and borderline than benign tumors (p < 0.05), and negatively correlated with vascular invasion, lymphatic invasion and FIGO staging of ovarian cancer (p < 0.05). ING5 protein was less expressed in primary cancer than normal ovary (p < 0.05). There was a negative correlation between ING5 mRNA expression and the overall or progression-free survival time of the cancer patients with Grade 2, Grade 3, and stage I cancer (p < 0.05). Immunohistochemically, ING5 was less expressed in serous and mucinous adenocarcinoma than miscellaneous subtypes, and positively correlated with dedifferentiation and ki-67 expression of ovarian cancer (p < 0.05). These data suggested that down-regulated ING5 expression might be involved in ovarian carcinogenesis possibly by suppressing aggressive phenotypes, including proliferation, tumor growth, migration, invasion, and anti-apoptosis.

// Xiao-Qing Ding 1 , Shuang Zhao 1 , Lei Yang 1 , Xin Zhao 1 , Gui-Feng Zhao 1 , Shu-Peng Zhao 2 , Zhi-Jie Li 1 and Hua-Chuan Zheng 1 1 Department of Experimental Oncology and Animal Center, Shengjing Hospital of China Medical University, Shenyang 110004, China 2 Department of Surgery, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou 121001, China Correspondence to: Hua-Chuan Zheng, email: zheng_huachuan@hotmail.com Keywords: breast cancer, ING5, pathogenesis, aggressiveness, progression Received: January 16, 2017 Accepted: May 03, 2017 Published: May 17, 2017 ABSTRACT Here, we found that ING5 overexpression resulted in a lower proliferation, reduced glucose metabolism, S arrest, decreased migration and invasion, apoptotic induction, fat accumulation, autophagy, senescence and mesenchymal-epithelial–transition of breast cancer cells. It also suppressed the tumor growth of breast cancer cells by inhibiting proliferation, inducing apoptosis and autophagy. ING5-mediated chemoresistance was positively linked to Akt and NF-κB activation, MRP1 and GST-π overexpression, and FBXW7 hypoexpression. ING5 expression was higher in breast cancer than normal tissue at both mRNA and protein levels. ING5 mRNA expression was positively correlated with relapse- and distant metastasis-free survival rates. Nuclear ING5 expression showed gradual decrease from breast normal tissue, fibroadenoma, adenomatosis, primary to metastatic cancers, while versa for cytoplasmic ING5. Nuclear ING5 expression was negatively correlated with distant metastasis and p53 hypoexpression, while cytoplasmic ING5 expression was positively correlated with tumor size and ER expression. These data suggested that up-regulated expression and nucleocytoplasmic translocation of ING5 protein were observed in breast cancer. The higher expression of nuclear ING5 was inversely linked to worse clinicopathological behaviors of breast cancer by in vivo and vitro reversing aggressive phenotypes. Therefore, it should be employed as a biomarker to indicate the tumorigenesis and aggressiveness of breast cancer, and as a potential target for gene therapy.

To elucidate the anti-tumor effects and molecular mechanisms of ING5 on glioma cells, we overexpressed it in U87 cells, and examined the phenotypes and their relevant molecules. It was found that ING5 overexpression suppressed proliferation, energy metabolism, migration, invasion, and induced G2/M arrest, apoptosis, dedifferentiation, senescence, mesenchymal- epithelial transition and chemoresistance to cisplatin, MG132, paclitaxel and SAHA in U87 cells. There appeared a lower expression of N-cadherin, Twist, Slug, Zeb1, Zeb2, Snail, Ac-H3, Ac-H4, Cdc2, Cdk4 and XIAP, but a higher expression of Claudin 1, Histones 3 and 4, p21, p53, Bax, β-catenin, PI3K, Akt, and p-Akt in ING5 transfectants. ING5 overexpression suppressed tumor growth of U87 cells in nude mice by inhibiting proliferation and inducing apoptosis. Down-regulated ING5 expression was closely linked to the tumorigenesis and histogenesis of glioma. These data indicated that ING5 expression might be considered as a good marker for the tumorigenesis and histogenesis of gliomas. It might be employed as a potential target for gene therapy of glioma. PI3K/Akt or β-catenin/TCF-4 activation might be positively linked to chemotherapeutic resistance, mediated by ING5.

Background The inhibitor of growth (ING) gene family of tumor suppressors is involved in multiple cellular functions such as cell cycle regulation, apoptosis, and chromatin remodeling. ING5 is a new member of the ING family whose function and regulation remain largely unknown. Methods Quantitative real-time PCR and western blot were used to examine the expression levels of ING5 in breast cancer tissues. The miRNAs that potentially targeted ING5 were determined by bioinformatics analysis and luciferase reporter assay. Cell viability assay, transwell invasion and apoptosis assay were used to characterize the changes induced by overexpressing or knocking down miR-24 or ING5. Hematoxylin and eosin (H&E) staining and immunohistochemical staining for ING5 and Ki-67 were used for xenograft assays in BALB/c nude mice. Results We showed that the ING5 protein rather than the mRNA, was significantly downregulated in breast cancer tissues. We also investigated the potential function of ING5 in breast tumorigenesis and found that ING5 suppressed the proliferation and invasion of breast cancer cells and promoted their apoptosis. Furthermore, we explored the molecular mechanisms accounting for the dysregulation of ING5 in breast cancer cells and identified an oncomiR, miR-24, as a direct upstream regulator of ING5. We revealed that miR-24 had the opposite effects to those of ING5 on breast cancer cells and could accelerate xenografted tumor growth in vivo. Conclusion Our findings uncover the tumor-suppressive role of ING5 and the regulatory pathway of ING5 in breast cancer and may provide insights into the molecular mechanisms of breast carcinogenesis. Electronic supplementary material The online version of this article (doi:10.1186/s12943-017-0658-z) contains supplementary material, which is available to authorized users.

// Xin-Li Liu 1, * , Xu-Tao Zhang 1, * , Jin Meng 2, 3, * , Hong-Fei Zhang 1 , Yong Zhao 4 , Chen Li 1 , Yang Sun 1 , Qi-Bing Mei 1 , Feng Zhang 1 and Tao Zhang 2 1 Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi’an, China 2 Department of Thoracic Surgery, Tangdu Hospital, Fourth Military Medical University, Xi’an, China 3 Department of Pharmcy, Hospital of PLA, Beijing, China 4 Laboratory Animal Center, Fourth Military Medical University, Xi’an, China * These authors contributed equally to this work Correspondence to: Tao Zhang, email: zhangft@fmmu.edu.cn Feng Zhang, email: zhangf037@163.com Keywords: ING5, lung cancer, epithelial mesenchymal transition (EMT), EGFR/PI3K/Akt, IL-6/STAT3 Received: November 24, 2016 Accepted: April 11, 2017 Published: April 21, 2017 ABSTRACT ING5 belongs to the Inhibitor of Growth (ING) candidate tumor suppressor family, whose functions have been involved in the regulation of chromatin remodeling, cell cycle progression, proliferation and apoptosis. Our previous study has shown that ING5 overexpression inhibits lung cancer aggressiveness via suppressing epithelial to mesenchymal transition (EMT). However, the mechanisms remain largely unknown. In the current study, by Phospho-Kinase array and western blot, we have defined significantly upregulated EGFR/PI3K/Akt and IL-6/STAT3 oncogenic signaling pathways in ING5 knockdown A549 cells, which could be downregulated by ING5 overexpression. PI3K inhibitor ZSTK474 or STAT3 inhibitor Niclosamide not only abolished ING5 knockdown-promoted proliferation, colony formation, migration and invasion of lung cancer A549 cells, but also impaired ING5 knockdown-stimulated metastasis of cancer cells in mouse xenograft models with tail vein injection of A549 cells. Furthermore, treatment with ZSTK474 or Niclosamide decreased protein level of EGFR, p-Akt, IL-6 and p-STAT3, and reversed ING5 knockdown-promoted EMT, as indicated by downregulated expression of EMT marker E-cadherin, an epithelial marker, increased expression of N-cadherin, a mesenchymal marker, and EMT-related transcription factors including Snail, Slug, Smad3 and Twist. Taken together, these results demonstrate that loss of ING5 enhances aggressiveness of lung cancer cells by promoting EMT via activation of EGFR/PI3K/Akt and IL-6/STAT3 signaling pathways.

Non-small cell lung cancer (NSCLC) has been the leading cause of cancer-related death worldwide, over the last few decades. Survival remains extremely poor in the metastatic setting and, consequently, innovative therapeutic strategies are urgently needed. Inhibitor of Growth Gene 2 (ING2) is a core component of the mSin3A/Histone deacetylases complex (HDAC), which controls the chromatin acetylation status and modulates gene transcription. This gene has been characterized as a tumor suppressor gene and its status in cancer has been scarcely explored. In this review, we focused on ING2 and other mSin3A/HDAC member statuses in NSCLC. Taking advantage of existing public databases and known pharmacological properties of HDAC inhibitors, finally, we proposed a therapeutic model based on an ING2 biomarker-guided strategy.

// Shuang Zhao 1 , Xue-feng Yang 1 , Dao-fu Shen 1 , Yang Gao 1 , Shuai Shi 1 , Ji-cheng Wu 1 , Hong-xu Liu 2 , Hong-zhi Sun 1 , Rong-jian Su 3 , Hua-chuan Zheng 1, 3 1 Cancer Center, Key Laboratory of Brain and Spinal Cord Injury of Liaoning Province, and Animal Center, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, 121001, China 2 Department of Thoracic Surgery, The First Affiliated Hospital of China Medical University, Shenyang, 110001, China 3 Life Science Institute of Jinzhou Medical University, Jinzhou, 121001, China Correspondence to: Hua-chuan Zheng, email: zheng_huachuan@hotmail.com Keywords: lung cancer, ING5, pathogenesis, aggressiveness, prognosis Received: February 06, 2016 Accepted: May 28, 2016 Published: July 09, 2016 ABSTRACT ING5 can interact with p53, thereby inhibiting cell growth and inducing apoptosis. We found that ING5 overexpression not only inhibited proliferation, migration, and invasion, but also induced G2 arrest, differentiation, autophagy, apoptosis, glycolysis and mitochondrial respiration in lung cancer cells. ING5 transfection up-regulated the expression of Cdc2, ATG13, ATG14, Beclin-1, LC-3B, AIF, cytochrome c, Akt1/2/3, ADFP, PFK-1 and PDPc, while down-regulated the expression of Bcl-2, XIAP, survivin,β-catenin and HXK1. ING5 transfection desensitized cells to the chemotherapy of MG132, paclitaxel, and SAHA, which paralleled with apoptotic alteration. ING5 overexpression suppressed the xenograft tumor growth by inhibiting proliferation and inducing apoptosis. ING5 expression level was significantly higher in normal tissue than that in lung cancer at both protein and mRNA levels. Nuclear ING5 expression was positively correlated with ki-67 expression and cytoplasmic ING5 expression. Cytoplasmic ING5 expression was positively associated with lymph node metastasis, and negatively with age, lymphatic invasion or CPP32 expression. ING5 expression was different in histological classification: squamous cell carcinoma > adenocarcinoma > large cell carcinoma > small cell carcinoma. Taken together, our data suggested that ING5 downregulation might involved in carcinogenesis, growth, and invasion of lung cancer and could be considered as a promising marker to gauge the aggressiveness of lung cancer. It might be employed as a potential target for gene therapy of lung cancer.

Neuroblastoma is the most common extracranial solid neuroendocrine cancer and is one of the leading causes of death in children. To improve clinical outcomes and prognosis, discovering new promising drugs and targeted medicine is essential. We found that applying Suberoylanilide hydroxamic acid (SAHA; Vorinostat, a histone deacetylase inhibitor) and MG132 (a proteasome inhibitor) to SH‐SY5Y cells synergistically suppressed proliferation, glucose metabolism, migration, and invasion and induced apoptosis and cell cycle arrest. These effects occurred both concentration and time dependently and were associated with the effects observed with inhibitor of growth 5 (ING5) overexpression. SAHA and MG132 treatment increased the expression levels of ING5, PTEN, p53, Caspase‐3, Bax, p21, and p27 but decreased the expression levels of 14‐3‐3, MMP‐2, MMP‐9, ADFP, Nanog, c‐myc, CyclinD1, CyclinB1, and Cdc25c concentration dependently, similar to ING5. SAHA may downregulate miR‐543 and miR‐196‐b expression to enhance the translation of ING5 protein, which promotes acetylation of histones H3 and H4. All three proteins (ING5 and acetylated histones H3 and H4) were recruited to the promoters of c‐myc, Nanog, CyclinD1, p21, and p27 for complex formation, thereby regulating the mRNA expression of downstream genes. ING5 overexpression and SAHA and/or MG132 administration inhibited tumor growth in SH‐SY5Y cells by suppressing proliferation and inducing apoptosis. The expression of acetylated histones H3 and ING5 may be closely linked to the tumor size of neuroblastomas. In summary, SAHA and/or MG132 can synergistically suppress the malignant phenotypes of neuroblastoma cells through the miRNA‐ING5‐histone acetylation axis and via proteasomal degradation, respectively. Therefore, the two drugs may serve as potential treatments for neuroblastoma.

// Yiyi Cao 1, * , Juan Chen 1, * , Dan Wang 1 , Hong Peng 1 , Xixi Tan 1 , Dongmei Xiong 1 , Ailong Huang 1, 2 , Hua Tang 1 1 Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China 2 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China * These authors have contributed equally to this work Correspondence to: Hua Tang, e-mail: tanghua86162003@cqmu.edu.cn Ailong Huang, e-mail: ahuang1964@163.com Keywords: HCC, HBV, miRNA, miR-331-3p, ING5 Received: May 14, 2015 Accepted: October 02, 2015 Published: October 13, 2015 ABSTRACT Hepatitis B virus (HBV) is a major risk factor for development and progression of hepatocellular carcinoma (HCC). It has been reported that viral infection can interfere with cellular microRNA (miRNA) expression and participate in the pathogenesis of oncogenicity. Our miRNAs array data indicated that miR-331-3p expression in HCC cell lines increased, but the relationship between miR-331-3p expression and HBV activity is unclear. Here, we observed elevated expression of miR-331-3p in different HCC cell lines expressing HBV. HBV, especially HBx, promotes miR-331-3p expression by enhancing its promoter activity. Using a miRNA target prediction database miRBase, we identified ING5 to be a novel target gene of miR-331-3p. miR-331-3p could inhibit ING5 expression by directly targeting its 3′-untranslated region (3′-UTR). As predicted, HBV was confirmed to repress ING5 at both mRNA and protein levels by promoting miR-331-3p expression. Our result indicated that miR-331-3p expression promotes proliferation of SMMC7721 cells by inhibiting ING5. ING5 overexpression promoted cell apoptosis in HCC cell lines. We also found ING5 expression was decreased in tumor tissue of HCC patient with HBV infection compared to its expression in para-carcinoma tissues. Conclusion: These results showed that miR-331-3p is upregulated by HBV and promotes proliferation of HCC cells though repression of ING5 expression. These data provide new insights for understanding the mechanisms of HBV-related HCC pathogenesis.

Lysine residues are subject to many forms of covalent modification and one such modification is acetylation of the ε-amino group. Initially identified on histone proteins in the 1960s, lysine acetylation is now considered as an important form of post-translational modification that rivals phosphorylation. However, only about a dozen of human lysine acetyltransferases have been identified. Among them are MOZ (monocytic leukemia zinc finger protein; a.k.a. MYST3 and KAT6A) and its paralog MORF (a.k.a. MYST4 and KAT6B). Although there is a distantly related protein in Drosophila and sea urchin, these two enzymes are vertebrate-specific. They form tetrameric complexes with BRPF1 (bromodomain- and PHD finger-containing protein 1) and two small non-catalytic subunits. These two acetyltransferases and BRPF1 play key roles in various developmental processes; for example, they are important for development of hematopoietic and neural stem cells. The human KAT6A and KAT6B genes are recurrently mutated in leukemia, non-hematologic malignancies, and multiple developmental disorders displaying intellectual disability and various other abnormalities. In addition, the BRPF1 gene is mutated in childhood leukemia and adult medulloblastoma. Therefore, these two acetyltransferases and their partner BRPF1 are important in animal development and human disease.

// Feng Zhang 1,* , Xutao Zhang 1,* , Jin Meng 2,3,* , Yong Zhao 4 , Xinli Liu 1 , Yanxia Liu 5 , Yukun Wang 1 , Yuhua Li 1 , Yang Sun 1 , Zhipeng Wang 1 , Qibing Mei 1 and Tao Zhang 6 1 Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi’an, China 2 Department of Oncology, Tangdu Hospital, The Fourth Military Medical University, Xi’an, China 3 Department of Pharmacy, No. 309 Hospital of PLA, Beijing, China 4 Laboratory Animal Center, Fourth Military Medical University, Xi’an, China 5 National Engineering Center for Biochip, Shanghai, China 6 Department of Thoracic Surgery, Tangdu Hospital, Fourth Military Medical University, Xi’an, China * These authors have contributed equally to this work Correspondence to: Tao Zhang, email: // Qibing Mei, email: // Keywords : ING5, lung cancer, proliferation, invasion, EMT Received : December 15, 2014 Accepted : March 20, 2015 Published : April 15, 2015 Abstract The proteins of the Inhibitor of Growth (ING) candidate tumor suppressor family are involved in multiple cellular functions such as cell cycle regulation, apoptosis, and chromatin remodeling. ING5 is the new member of the family whose actual role in tumor suppression is not known. Here we show that ING5 overexpression in lung cancer A549 cells inhibited cell proliferation and invasiveness, while ING5 knockdown in lung cancer H1299 cells promoted cell aggressiveness. ING5 overexpression also abrogated tumor growth and invasive abilities of lung cancer cells in mouse xenograft models. Further study showed that ING5 overexpression inhibited EMT indicated by increase of E-cadherin and decrease of N-cadherin, Snail and slug at mRNA and protein levels, which was accompanied with morphological changes. cDNA microarray and subsequent qRT-PCR validation revealed that ING5 significantly downregulated expression of EMT (epithelial to mesenchymal transition)-inducing genes including CEACAM6, BMP2 and CDH11. Clinical study by tissue microarray showed that nuclear ING5 negatively correlated with clinical stages and lymph node metastasis of lung cancer. Furthermore, high level of nuclear ING5 was associated with a better prognosis. Taken together, these findings uncover an important role for ING5 as a potent tumor suppressor in lung cancer growth and metastasis.

Here, we found that ING5 overexpression increased autophagy, differentiation, and decreased proliferation, apoptosis, migration, invasion and lamellipodia formation in gastric cancer cells, while ING5 knockdown had the opposite effects. In SGC-7901 transfectants, ING5 overexpression caused G1 arrest, which was positively associated with 14-3-3 overexpression, Cdk4 and c-jun hypoexpression. The induction of Bax hypoexpression, Bcl-2, survivin, 14-3-3, PI3K, p-Akt and p70S6K overexpression by ING5 decreased apoptosis in SGC-7901 cells. The hypoexpression of MMP-9, MAP1B and flotillin 2 contributed to the inhibitory effects of ING5 on migration and invasion of SGC-7901 cells. ING5 overexpression might activate both β-catenin and NF-κB pathways in SGC-7901 cells, and promote the expression of down-stream genes (c-myc, VEGF, Cyclin D1, survivin, and interleukins). Compared with the control, ING5 transfectants displayed drug resistance to triciribine, paclitaxel, cisplatin, SAHA, MG132 and parthenolide, which was positively related to their apoptotic induction and the overexpression of chemoresistance-related genes (MDR1, GRP78, GRP94, IRE, CD147, FBXW7, TOP1, TOP2, MLH1, MRP1, BRCP1 and GST-π). ING5 expression was higher in gastric cancer than matched mucosa. It was inversely associated with tumor size, dedifferentiation, lymph node metastasis and clinicopathological staging of cancer. ING5 overexpression suppressed growth, blood supply and lung metastasis of SGC-7901 cells by inhibiting proliferation, enhancing autophagy and apoptosis in xenograft models. It was suggested that ING5 expression might be employed as a good marker for gastric carcinogenesis and subsequent progression by inhibiting proliferation, growth, migration, invasion and metastasis. ING5 might induce apoptotic and chemotherapeutic resistances of gastric cancer cells by activating β-catenin, NF-κB and Akt pathways.

As the major barrier to curative cancer chemotherapy, chemoresistance presents a formidable challenge to both cancer researchers and clinicians. We have previously shown that the bladder cancer (BCa) cell line 5637 is significantly more sensitive to the cytoxicity of five chemotherapeutic agents than H-bc cells. Using an RNA-seq-based omic analysis and validation at both the mRNA and protein levels, we found that the inhibitor of growth 5 (ING5) gene was upregulated in 5637 cells compared with H-bc cells, indicating that it has an inhibitory role in BCa chemoresistance. siRNA-mediated inhibition of ING5 increased the chemoresistance and inhibited the DNA damage response pathway in 5637 cells. Conversely, forced expression of EGFP-ING5 decreased the chemoresistance of and activated the DNA damage response pathway in H-bc cells. We also showed that ING5 gene expression is inhibited by miR-193a-3p and is instrumental in miR-193a-3p's role in activating BCa chemoresistance. Our results demonstrate both the role and mechanism of inhibition of BCa chemoresistance by ING5.

Background We aimed to investigate the function of miR-1307 in chemoresistance and to explore its chemoresistance mechanism in ovarian cancer. Methods IC50 determination was used to test the chemoresistance profling in ovarian cancer cells. QRT-PCR or western blot was used to validate the expression level of miR-1307 and candidate gene or protein. Colony formation assay and FITC-labeled enhanced Annexin V immunofluorescence were used to compare cell proliferation and apoptosis ability, respectively. The potential target gene and its biological function of miRNA-1307 were also analyzed. Bioinformatics and Luciferase Reporter Gene Assay were conducted to validate the regulation of miRNA-1307 on the ING5 expression. Xenografts assay was used to demonstrate the inhibiting effect of miR-1307 ASO and Taxol therapy against ovarian cancer in vivo. Results MiR-1307 was over-expressed in chemoresistant ovarian cancer cell line A2780/Taxol, and over-expression or loss of miR-1307 promoted or inhabited chemoresistance. And we also found that the over-expression of miR-1307 promoted proliferation and inhibited apoptosis in ovarian cancer cells. Besides, we demonstrated that ING5 was a direct target of miR-1307 and miR-1307 down-regulated the ING5 expression in ovarian cancer cells. Additionally, we showed that ING5 inhibited cell proliferation, promoted cell apoptosis and inhabited chemoresistance reversely. Furthermore, the up-regulated ability of cell apoptosis and down-regulated ability of chemoresistance following the loss of miR-1307 was reversed by adding ING5 siRNA in vitro. Finally, we proved the inhibiting effect of miR-1307 ASO and Taxol therapy by increasing the ING5 expression against ovarian cancer through xenografts assay in vivo. Conclusion Our results suggested that miR-1307 could promote ovarian cancer chemoresistance by targeting the ING5 expression and miR-1307 might serve as a therapeutic target for ovarian cancer.

Osteosarcoma is one of the most common primary malignant bone tumors. The inhibitor of growth family of protein 5 has been identified as a tumor suppressor in many cancers. In this study, we confirmed the downregulation of the both inhibitor of growth family of protein 5 and messenger RNA levels in cancer tissues using Western blot and real-time polymerase chain reaction. In order to find the antitumor roles of inhibitor of growth family of protein 5, osteosarcoma cells, HOS, and MG63 were transfected with the plasmid pCDNA-3.1-inhibitor of growth family of protein 5. Overexpression of Inhibitor of growth family of protein 5 could induce apoptosis and inhibit cell proliferation in osteosarcoma cells. Furthermore, Western blot analysis showed that p-Smad2, p-Smad3, and Smad4 were increased in inhibitor of growth family of protein 5-expressing osteosarcoma cells. Our results indicated that overexpression of inhibitor of growth family of protein 5 in osteosarcoma cells induces apoptosis by activating the Smad pathway, thus proposing a promising role for inhibitor of growth family of protein 5 in treatment of patients with osteosarcoma.

The inhibitor of growth (ING) family consists of five members, ING1-ING5. These proteins are involved in different cellular processes, including transcription, replication and apoptosis. There have been reports suggesting that some members of the ING family are deregulated in different tumors. In support, reduced ING1 protein levels have been observed in tumors, suggesting a function as tumor suppressor. There are two different functions postulated for ING5. On the one hand ING5 binds to trimethylated lysine 4 of histone H3 (H3K4me3) in vitro and recruits the histone acetyltransferases HBO1 and MOZ/MORF and consequently seems to be involved in gene transcription. On the other hand it is also known that ING5 binds MCM2, thereby interacting with origins of replication. HBO1 is also involved in these complexes. Together these findings suggest that ING5 has functions in replication, some may overlap with activities relevant for transcription. Furthermore it has been postulated that some of these activities depend on the ability of ING5 to interact with the tumor suppressor p53. The aim of this thesis was to investigate in more detail the function and regulation of ING5. In particular the control of ING5 function by phosphorylation should be addressed and clarified. In preliminary work we identified ING5 as a novel substrate of Cyclin E/CDK2. Developing and applying phospho-specific antibody allowed me to validate the ING5 phoshorylation at Threonin 152 both in vitro and in cells. Moreover I found that this phosphorylation is regulated during the cell cycle and accumulates in the S- and G2-phases of the cell cycle. Knockdown experiments were performed to clarify the biological relevance of ING5. The reduction of ING5 protein levels induced apoptosis. This is in contrast to previous findings demonstrating that the knockdown of ING1 induces proliferation. Surprisingly the induction of apoptosis in response to the ING5 knockdown was p53 independent, despite the fact that ING5 interacts, albeit weakly, with p53. A number of links suggested at least a functional interaction of ING5 with the oncoprotein Myc. This included the correlation of Myc chromatin binding with H3K4me3 mark, the interaction of Myc with and phosphorylation by Cyclin E/CDK2, and the ability of Myc to induce apoptosis independently of p53. Therefore a possible connection between ING5 and Myc was analyzed in the regulation of apoptosis. I was able to demonstrate a direct interaction between ING5 and Myc. In addition I found that ING5 regulates Myc-mediated apoptosis. Furthermore the correlation of these proteins in transcription was investigated and ING5 binding at promoters of Myc target genes was identified. These findings suggest that ING5 functions as a cofactor for the regulation of Myc target genes, possibly those involved in the control of apoptosis.

International audience

We analysed the loss of heterozygosity (LOH) of long arm of chromosome 2 by using 16 polymorphic microsatellite markers in 39 matched oral normal and cancer tissues, and defined the deletional mapping of the region with putative tumor suppressor genes. LOH was detected at least one location in 33 of 39 (85%) tumor tissues. Frequent deletions were detected at the locations of microsatellite markers, D2S2304 (35%), D2S111 (40%), D2S155 (35%), D2S1327 (29%), D2S164 (29%), D2S125 (68%) and D2S140 (32%). Three preferentially deleted regions at 2q21-24, 2q33-35 and 2q37.3 were observed. Several candidate tumor suppressor genes in these regions such as LRP1B, CASP8, CASP10, BARD1, ILKAP, PPP1R7, and ING5, are located. Further molecular analysis of each gene should be performed to clarify their roles in oral carcinogenesis.

The tumour suppressor protein p53 stops cell division by activating the expression of p21WAF1/CIP1, whenever it senses that a cells DNA is damaged. Thus, giving the cell a chance to repair the damaged DNA before its errors are duplicated and passed onto daughter cells. When p53 is mutated, it loses its protective function. This allows mutations to accumulate in other genes and leads to more than 50% of all human cancers. p21WAF1/CIP1 inhibits cyclin E/CDK2 complexes to prevent G1-S progression of cell cycle. Though the cyclin/CDK complexes are required for the orderly progression of the cell cycle, overexpression of cyclin E/CDK2 has been reported to lead to poor prognosis in breast cancer. The molecular mechanism underlying this is poorly understood. The current investigation was undertaken to elucidate the role of ING5, in relation to cyclin E/CDK2 activity and p53 function. ING5, which was identified in a novel approach for screening the substrates of cyclin E/CDK2 is a member of the ING family of proteins that inhibit growth. The in vitro and in vivo interaction experiments and the reporter gene assays demonstrate that ING5 interacts with p53 to strongly activate p53-mediated transactivation of the promoters of the p21, bax and mdm2 genes. The extensive mapping of their interaction domains showed that the PH domain of ING5 interacts with the DNA binding domain of p53 indicating that ING5 does not interfere with p53-MDM2 interaction. ING5 mediates apoptosis of breast cancer cells with an intact p53 pathway as demonstrated in MCF-7 cells. It was observed that overexpression of cyclin E/CDK2 negatively regulated ING5-mediated activation of p53 and apoptosis. This work for the first time also illustrates a member of the ING family to be interacting with p63 and p73. ING5 interacts with p63 and p73 both in vitro and in vivo to differentially modulate p63 and p73-mediated transactivation of bax, p21 and pig3 genes. While one important function of p53 is to prevent S phase entry in response to cellular stress by activating the CKI p21, which interferes with the activities of the cyclin /CDKs, the identification of ING5 provides the first example of a reverse regulatory relationship between p53 and CDK activity. The findings suggest that the molecular network of ING5-p53-p21-cyclin E/CDK2 is an example of a positive feed back loop. Therefore ING5 could be useful in therapies for treating cancers with an intact p53 pathway.