Potential Therapeutic Target In Cancer Research Articles

Abstract 3891: Efficacy of dinaciclib in hepatoblastoma through inhibition of cyclin dependent kinases

Abstract Introduction: Hepatoblastoma (HB) is the most frequent liver malignancy of childhood with an annual incidence of 1.5 per million and a survival rate less than 50%. Due to significant side effects and ineffectiveness of standard chemotherapy for relapse refractory disease, the treatment options are now shifting towards targeted therapies. Cyclin-dependent kinases (CDKs) are potential cancer therapeutic targets because of their critical role in promoting cell growth and regulating transcriptional processes. This study aims to assess the therapeutic efficacy of dinaciclib, cyclin-dependent kinase inhibitor, with HB in preclinical in vitroand in vivo models. Method: Dinaciclib was tested in patient derived cell lines (PDCL) from different patient derived xenograft (PDX) models using CellTiter-Glo Luminescent Viability assays. Dinaciclib was also assayed in vitro for cytotoxicity (MTT assay) and proliferation (CCK-8 assay). Differential expression of CDKs was checked by microarray analysis between normal liver and HB patients. Results were confirmed by immunoblotting assays. Immunoblotting assays were also used to see the effect of dinaciclib on CDK 1/2/5/9 and to assess the induction of apoptosis (PARP cleavage) in vitro. Dinaciclib was also tested in our orthotopic PDX models of high-risk HB. MRI and alpha-fetoprotein (AFP) ELISA were done to evaluate tumor growth. Tumor weights and volumes, as well as, immunohistochemistry were also used to assess effects of dinaciclib in vivo. Result: Dinaciclib suppressed cell proliferation and viability in a dose-dependent manner in all HB cell lines tested with IC50 in the low micromolar range (HepG2- 3.75; HepT1- 0.007; Huh6- 1.42; HB17- 0.72). Microarray analysis showed significant upregulation of CDK1 (p=0.0003), CDK2 (p=0.00023) and CDK9 (p=0.015) in HB patient samples, however, immunoblotting with dinaciclib-treated cells showed decreased expression of CDKs 1/2/5/9 as well as induction of apoptosis. Dinaciclib also showed in vivo inhibition of tumor growth compared to placebo in both PDX models (HB47: relative tumor volume p = 0.03, T/C ratio= 0.36, tumor weight p = 0.02; HB52: relative tumor volume p = 0.06, T/C ratio= 0.16, tumor weight p = 0.07). Conclusion: Dinaciclib treatment showed promising effects with preclinical HB cell lines and PDX models. Citation Format: Rohit K. Srivastava, Roma Patel, Andres F. Espinoza, Yang Yu, Richard S. Whitlock, Samuel Larson, Andrew Badachhape, Jianhua Yang, Sarah E. Woodfield, Sanjeev A. Vasudevan. Efficacy of dinaciclib in hepatoblastoma through inhibition of cyclin dependent kinases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3891.

TRAP1 Chaperones the Metabolic Switch in Cancer.

Mitochondrial function is dependent on molecular chaperones, primarily due to their necessity in the formation of respiratory complexes and clearance of misfolded proteins. Heat shock proteins (Hsps) are a subset of molecular chaperones that function in all subcellular compartments, both constitutively and in response to stress. The Hsp90 chaperone TNF-receptor-associated protein-1 (TRAP1) is primarily localized to the mitochondria and controls both cellular metabolic reprogramming and mitochondrial apoptosis. TRAP1 upregulation facilitates the growth and progression of many cancers by promoting glycolytic metabolism and antagonizing the mitochondrial permeability transition that precedes multiple cell death pathways. TRAP1 attenuation induces apoptosis in cellular models of cancer, identifying TRAP1 as a potential therapeutic target in cancer. Similar to cytosolic Hsp90 proteins, TRAP1 is also subject to post-translational modifications (PTM) that regulate its function and mediate its impact on downstream effectors, or ‘clients’. However, few effectors have been identified to date. Here, we will discuss the consequence of TRAP1 deregulation in cancer and the impact of post-translational modification on the known functions of TRAP1.

NPM1 promotes cell proliferation by targeting PRDX6 in colorectal cancer

Colorectal cancer is a malignant tumor that begins in the colorectal mucosal epithelium. NPM1 is a nucleolar phosphoprotein that has been linked to tumor progression in humans. NPM1 is significantly overexpressed in a variety of tumors, including colorectal cancer, but its role and mechanism in colorectal cancer remain unknown. Therefore, the purpose of this study was to discover the role of NPM1 in promoting colorectal cancer proliferation via PRDX6 and its molecular mechanism. NPM1 knockdown or overexpression inhibited or promoted the proliferation and cell cycle progression of HCT-116 and HT-29 colorectal cancer cells, respectively, according to our findings. Furthermore, NPM1 knockdown or overexpression increased or decreased intracellular ROS levels. Animal experiments revealed that NPM1 knockdown or overexpression inhibited or promoted the growth of colorectal cancer cells transplanted subcutaneously. NPM1 knockdown or overexpression reduced or increased PRDX6 expression and related enzyme activities, respectively, according to our findings. NPM1 formed a complex with CBX3 as evidenced by immunoprecipitation, and the double luciferase reporter gene assay confirmed that the CBX3-NPM1 complex promoted PRDX6 transcription. Our data support the role of NPM1 in promoting the proliferation of colorectal cancer, which may be accomplished by CBX3 promoting the expression of the antioxidant protein PRDX6 and thus inhibiting intracellular ROS levels. NPM1 and PRDX6 are potential colorectal cancer therapeutic targets.

LINC00963: A potential cancer diagnostic and therapeutic target.

Long intergenic noncoding RNA 00963 (LINC00963) is located on human chromosome 9q34.11. Aberrantly expressed LINC00963 often exerts oncogenic effects by regulating various cellular processes including proliferation, migration, invasion, EMT, and apoptosis. Overexpressed LINC00963 is associated with cancer clinicopathological features and poor cancer prognosis, and can be used in the diagnosis of hepatocellular carcinoma. LINC00963 can build a complex ceRNA network by competitively binding to 22 miRNAs in 14 cancers. LINC00963 can also directly regulate four downstream protein-coding genes. Specifically, LINC00963 promotes the transition of prostate cancer from an androgen-dependent mode to an androgen-independent mode by participating in the transactivation of EGFR. LINC00963 can bind EZH2 and inhibit p21 expression, thereby promoting glioma cell proliferation and invasion. In non-small cell lung cancer, LINC00963 can recruit NONO and CRTC, forming a positive feedback loop of LINC00963/NONO/CRTC/CREB/LINC00963, thereby promoting cancer cell metastasis. LINC00963 is involved in the PI3K/AKT signaling pathway, Wnt signaling pathway, AMPK signaling pathway, and MAPK signaling pathway. Furthermore, LINC00963 is associated with drug resistance in oral squamous cell carcinoma (cisplatin and 5-fluorouracil) and gastric cancer (oxaliplatin) and predicts neoadjuvant efficacy of taxane-anthracyclines in breast cancer. This work systematically reviewed the clinical value of abnormal expression of LINC00963 in various tumors, demonstrated the complex molecular mechanism of LINC00963, and provided directions for future related research.

SIRT1 regulates mitotic catastrophe via autophagy and BubR1 signaling.

Mitotic catastrophe (MC) is a suppressive mechanism that mediates the elimination of mitosis-deficient cells through apoptosis, necrosis or senescence after M phase block. SIRT1 is involved in the regulation of several cellular processes, including autophagy. However, the relationship between SIRT1 and MC has been largely obscure. Our study highlights that SIRT1 might be involved in the regulation of MC. We have shown that degradation of the SIRT1 protein via proteasome and lysosomal pathway was accompanied by MC induced via BMH-21. Overexpression of SIRT1 alleviated MC by decreasing the proportion of apoptotic and multinuclear cells induced by G2/M block and triggered autophagy whereas knockdown of SIRT1 aggravated MC and repressed autophagy. Furthermore, we found that serum starvation triggered autophagy evidently generated lower MC whereas siRNA of ATG5/7 suppressed autophagy leading to higher MC. ChIP analysis revealed that SIRT1 could bind to the promoter of BubR1, a component of spindle assembly checkpoint (SAC), to upregulate its expression. Overexpression of BubR1 decreased MC whereas knockdown of BubR1 increased it. These results reveal that SIRT1 regulates MC through autophagy and BubR1 signaling, and provide evidence for SIRT1, autophagy and BubR1 being the potential cancer therapeutic targets.

A widely expressed free immunoglobulin κ chain with a unique Vκ4-1/Jκ3 pattern promotes colon cancer invasion and metastasis by activating the integrin β1/FAK pathway

Historically, immunoglobulin (Ig) has been known as an antibody and is expressed only in B lineage cells; importantly, Ig light chains are conjugated to heavy chains to form intact Igs. However, in this study, we found a free Igκ light chain with a unique Vκ4-1/Jκ3 rearrangement (Vκ4-1/Jκ3-FLC) that was widely expressed in different non-B lineages and was overexpressed in cancer cells. Further study indicated that Vκ4-1/Jκ3-FLC was hydrophobic, formed obvious insoluble deposits in the extracellular matrix (ECM) and existed in free form. Functional analyses demonstrated that Vκ4-1/Jκ3-FLC promoted the proliferation, migration and metastasis of colon cancer cells in vitro and in vivo. Mechanistically, Vκ4-1/Jκ3-FLC bound to integrin β1 and activated the FAK and Src pathways. More importantly, specific antibodies against the variable region of Vκ4-1/Jκ3-FLC significantly inhibited the growth of colon cancer tumors. Our findings suggested that Vκ4-1/Jκ3-FLC is a novel ECM protein and integrin β1 ligand and that it is involved in cancer progression and is a potential therapeutic target in cancer, particularly colon cancer.

The roles of osteoprotegerin in cancer, far beyond a bone player.

Osteoprotegerin (OPG), also known as tumor necrosis factor receptor superfamily member 11B (TNFRSF11B), is a member of the tumor necrosis factor (TNF) receptor superfamily. Characterized by its ability to bind to receptor activator of nuclear factor kappa B ligand (RANKL), OPG is critically involved in bone remodeling. Emerging evidence implies that OPG is far beyond a bone-specific modulator, and is involved in multiple physiological and pathological processes, such as immunoregulation, vascular function, and fibrosis. Notably, numerous preclinical and clinical studies have been conducted to assess the participation of OPG in tumorigenesis and cancer development. Mechanistic studies have demonstrated that OPG is involved in multiple hallmarks of cancer, including tumor survival, epithelial to mesenchymal transition (EMT), neo-angiogenesis, invasion, and metastasis. In this review, we systematically summarize the basis and advances of OPG from its molecular structure to translational applications. In addition to its role in bone homeostasis, the physiological and pathological impacts of OPG on human health and its function in cancer progression are reviewed, providing a comprehensive understanding of OPG. We aim to draw more attention to OPG in the field of cancer, and to propose it as a promising diagnostic or prognostic biomarker as well as potential therapeutic target for cancer.

Discovery, optimization and evaluation of 1-(indolin-1-yl)ethan-1-ones as novel selective TRIM24/BRPF1 bromodomain inhibitors

TRIM24 (tripartite motif-containing protein 24) and BRPF1 (bromodomain and PHD finger containing protein 1) are epigenetics “readers” and potential therapeutic targets for cancer and other diseases. Here we describe the structure-guided design of 1-(indolin-1-yl)ethan-1-ones as novel TRIM24/BRPF1 bromodomain inhibitors. The representative compound 20l (Y08624) is a new TRIM24/BRPF1 dual inhibitor, with IC50 values of 0.98 and 1.16 μM, respectively. Cellular activity of 20l was validated by viability assay in prostate cancer (PC) cell lines. In PC xenograft models, 20l suppressed tumor growth (50 mg/kg/day, TGI = 53%) without exhibiting noticeable toxicity. Compound 20l represents a versatile starting point for the development of more potent TRIM24/BRPF1 inhibitors.

PI3K/Akt/mTOR Pathway and Its Role in Cancer Therapeutics: Are We Making Headway?

Cancer is a severe public health issue that is a leading cause of mortality globally. It is also an impediment to improving life expectancy worldwide. Furthermore, the global burden of cancer incidence and death is continuously growing. Current therapeutic options are insufficient for patients, and tumor complexity and heterogeneity necessitate customized medicine or targeted therapy. It is critical to identify potential cancer therapeutic targets. Aberrant activation of the PI3K/AKT/mTOR pathway has a significant role in carcinogenesis. This review summarized oncogenic PI3K/Akt/mTOR pathway alterations in cancer and various cancer hallmarks associated with the PI3K/AKT/mTOR pathway, such as cell proliferation, autophagy, apoptosis, angiogenesis, epithelial-to-mesenchymal transition (EMT), and chemoresistance. Importantly, this review provided recent advances in PI3K/AKT/mTOR inhibitor research. Overall, an in-depth understanding of the association between the PI3K/AKT/mTOR pathway and tumorigenesis and the development of therapies targeting the PI3K/AKT/mTOR pathway will help make clinical decisions.

Identify a DNA Damage Repair Gene Signature for Predicting Prognosis and Immunotherapy Response in Cervical Squamous Cell Carcinoma.

The DNA damage repair (DDR) genes are increasingly gaining attention as potential therapeutic targets in cancers. In this study, we identified the DDR genes associated with the tumor mutation burden (TMB) and prognosis of cervical squamous cell carcinoma (CESC) based on The Cancer Genome Atlas (TCGA) database. Through LASSO Cox regression, the prognostic signature involving five DDR genes (ACTR2, TEX12, UBE2V1, HSF1, and FBXO6) was established, and the risk score was identified as an independent risk factor for CESC. The nomogram consisting of the five genes accurately predicted the overall survival (OS) and the immunotherapeutic response of CESC patients. Finally, the loss of the copies of the transcription factor (TF) SP140 in CESC patients may decrease the expression of FBXO6, improve DNA repair function, and reduce the diversity of neoantigens, thereby lowering the response to immunotherapies. Therefore, the DDR gene signature is a novel prognostic model and a biomarker for immunotherapies in CESC patients.

Advance of SOX Transcription Factors in Hepatocellular Carcinoma: From Role, Tumor Immune Relevance to Targeted Therapy.

Simple SummaryHepatocellular carcinoma (HCC) is one of the deadliest human health burdens worldwide. However, the molecular mechanism of HCC development is still not fully understood. Sex determining region Y-related high-mobility group box (SOX) transcription factors not only play pivotal roles in cell fate decisions during development but also participate in the initiation and progression of cancer. Given the significance of SOX factors in cancer and their ‘undruggable’ properties, we summarize the role and molecular mechanism of SOX family members in HCC and the regulatory effect of SOX factors in the tumor immune microenvironment (TIME) of various cancers. For the first time, we analyze the association between the levels of SOX factors and that of immune components in HCC, providing clues to the pivotal role of SOX factors in the TIME of HCC. We also discuss the opportunities and challenges of targeting SOX factors for cancer.Sex determining region Y (SRY)-related high-mobility group (HMG) box (SOX) factors belong to an evolutionarily conserved family of transcription factors that play essential roles in cell fate decisions involving numerous developmental processes. In recent years, the significance of SOX factors in the initiation and progression of cancers has been gradually revealed, and they act as potential therapeutic targets for cancer. However, the research involving SOX factors is still preliminary, given that their effects in some leading-edge fields such as tumor immune microenvironment (TIME) remain obscure. More importantly, as a class of ‘undruggable’ molecules, targeting SOX factors still face considerable challenges in achieving clinical translation. Here, we mainly focus on the roles and regulatory mechanisms of SOX family members in hepatocellular carcinoma (HCC), one of the fatal human health burdens worldwide. We then detail the role of SOX members in remodeling TIME and analyze the association between SOX members and immune components in HCC for the first time. In addition, we emphasize several alternative strategies involved in the translational advances of SOX members in cancer. Finally, we discuss the alternative strategies of targeting SOX family for cancer and propose the opportunities and challenges they face based on the current accumulated studies and our understanding.

MTOR-Mediated Regulation of Immune Responses in Cancer and Tumor Microenvironment.

The mechanistic/mammalian target of rapamycin (mTOR) is a downstream mediator in the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways, which plays a pivotal role in regulating numerous cellular functions including cell growth, proliferation, survival, and metabolism by integrating a variety of extracellular and intracellular signals in the tumor microenvironment (TME). Dysregulation of the mTOR pathway is frequently reported in many types of human tumors, and targeting the PI3K/Akt/mTOR signaling pathway has been considered an attractive potential therapeutic target in cancer. The PI3K/Akt/mTOR signaling transduction pathway is important not only in the development and progression of cancers but also for its critical regulatory role in the tumor microenvironment. Immunologically, mTOR is emerging as a key regulator of immune responses. The mTOR signaling pathway plays an essential regulatory role in the differentiation and function of both innate and adaptive immune cells. Considering the central role of mTOR in metabolic and translational reprogramming, it can affect tumor-associated immune cells to undergo phenotypic and functional reprogramming in TME. The mTOR-mediated inflammatory response can also promote the recruitment of immune cells to TME, resulting in exerting the anti-tumor functions or promoting cancer cell growth, progression, and metastasis. Thus, deregulated mTOR signaling in cancer can modulate the TME, thereby affecting the tumor immune microenvironment. Here, we review the current knowledge regarding the crucial role of the PI3K/Akt/mTOR pathway in controlling and shaping the immune responses in TME.

High SIRPA Expression Predicts Poor Prognosis and Correlates with Immune Infiltrates in Patients with Esophageal Carcinoma.

Background Signal regulatory protein alpha (SIRPA) is an inhibitory receptor expressed in macrophages and a potential therapeutic target in cancers. This study aims to investigate the functional role of SIRPA in esophageal carcinoma (ESCA). Methods Based on the Oncomine and The Cancer Genome Atlas (TCGA) database, SIRPA expression and clinical value were determined. Gene set enrichment analysis (GSEA) was performed to predict the mechanism underlying the oncogene role of SIRPA. Spearman's correlation analysis was used to analyze the effects of SIRPA on the molecular relationship and immune landscape. Results SIRPA was highly expressed across Oncomine and TCGA databases and correlated with poor overall survival and disease-specific survival. There was an expression difference among clinical characteristics. Functional annotation showed that cancer-related biological function and pathways were enriched in the high SIRPA expression group. Besides, SIRPA strongly and extensively affected the immune infiltrates. Conclusion SIRPA might be an oncogene and a target of immunotherapy in ESCA.

MicroRNA-101-3p Suppresses Cancer Cell Growth by Inhibiting the USP47-Induced Deubiquitination of RPL11.

Simple SummaryAn abnormal expression of microRNA is commonly observed in cancer. Since a single miRNA can target numerous genes, it is important to understand the exact mechanism for the regulation of cancer growth by miRNAs. Here, we show that miR-101-3p, which is downregulated in several cancers, regulates RPL11 ubiquitination by targeting USP47, thereby controlling p53 levels by affecting the localization of RPL11 and its interaction with MDM2. Our results provide a novel mechanism for the inhibition of cancer cell growth by miR-101-3p, and suggest that miR-101-3p could be a potential target as an anticancer agent.MicroRNAs (miRNAs) are a class of small non-coding RNA molecules that regulate a countless number of genes in the cell, and the aberrant expression of miRNA can lead to cancer. Here, we demonstrate that miR-101-3p regulates the RPL11–MDM2–p53 pathway by targeting ubiquitin-specific peptidase 47 (USP47), consequently inhibiting cancer cell proliferation. We confirm that miR-101-3p directly binds to the 3′-UTR region of the USP47 gene and inhibits USP47 expression. In addition, the overexpression of miR-101-3p suppresses cell proliferation in a p53-dependent manner. MiR-101-3p promotes interaction between RPL11 and MDM2 by inducing the translocation of RPL11 from the nucleolus to the nucleoplasm, thus preventing the MDM2-mediated proteasomal degradation of p53. However, these phenomena are restored by the overexpression of USP47, but not by its catalytically inactive form. Indeed, miR-101-3p regulates RPL11 localization and its interaction with MDM2 by inhibiting the USP47-induced deubiquitination of RPL11. Finally, the expression of miR-101-3p is downregulated in lung cancer patients, and the patients with low miR-101-3p expression exhibit a lower survival rate, indicating that miR-101-3p is associated with tumorigenesis. Together, our findings suggest that miR-101-3p functions as a tumor suppressor by targeting USP47 and could be a potential therapeutic target for cancers.

The Role of Long Non-Coding RNAs in the Tumor Immune Microenvironment.

Tumorigenesis is a complicated process caused by successive genetic and epigenetic alterations. The past decades demonstrated that the immune system affects tumorigenesis, tumor progression, and metastasis. Although increasing immunotherapies are revealed, only a tiny proportion of them are effective. Long non-coding RNAs (lncRNAs) are a class of single-stranded RNA molecules larger than 200 nucleotides and are essential in the molecular network of oncology and immunology. Increasing researches have focused on the connection between lncRNAs and cancer immunotherapy. However, the in-depth mechanisms are still elusive. In this review, we outline the latest studies on the functions of lncRNAs in the tumor immune microenvironment. Via participating in various biological processes such as neutrophil recruitment, macrophage polarization, NK cells cytotoxicity, and T cells functions, lncRNAs regulate tumorigenesis, tumor invasion, epithelial-mesenchymal transition (EMT), and angiogenesis. In addition, we reviewed the current understanding of the relevant strategies for targeting lncRNAs. LncRNAs-based therapeutics may represent promising approaches in serving as prognostic biomarkers or potential therapeutic targets in cancer, providing ideas for future research and clinical application on cancer diagnosis and therapies.

Identification of a Schistosoma japonicum MicroRNA That Suppresses Hepatoma Cell Growth and Migration by Targeting Host FZD4 Gene.

Previous studies have demonstrated miRNAs derived from plants and parasites can modulate mammalian gene expression and cell phenotype in a cross-kingdom manner, leading to occurrence of diseases or strengthening resistance of host to diseases such as cancer. In this study, we identified a schistosome miRNA (named Sja-miR-71a) through screening of 57 Schistosoma japonicum miRNAs that exerts antitumor activity in vitro and in vivo models. We demonstrated presence of this parasite miRNA in liver cells during infection. We showed that Sja-miR-71a arrested cell cycle at G0/G1 phase of hepatoma cell lines and inhibited cell proliferation in vitro. The HepG2 transfected with Sja-miR-71a mimics displayed significant reduction of migration and colony formation. Further, growth of the tumor cells transfected with the Sja-miR-71a mimics was obviously suppressed in a xenograft mouse model. Mechanically, we found the antitumor activity of Sja-miR-71a was through targeting a host gene encoding Frizzled Class Receptor 4 (FZD4), as FZD4 small interfering RNAs (siRNAs) generated a similar inhibitory effect on the tumor. These data indicated that Sja-miR-71a is a tumor suppressor miRNA and suggested this parasite-derived miRNA as a potential therapeutic target for cancer.

A Pan-Cancer Study of KMT2 Family as Therapeutic Targets in Cancer.

Objective Exome sequencing studies have shown that the histone-lysine N-methyltransferase 2 (KMT2) gene is one of the most commonly mutated genes in a range of human malignancies and is linked to some of the most common and deadly solid tumors. However, the connection between this gene family's function and tumor type, immunological subtype, and molecular subtype dependency is still unknown. Methods We examine the expression patterns of the histone-lysine N-methyltransferase 2 (KMT2) gene, as well as their relationship to patient survival. We also used a pan-cancer analysis to link their function to immunological subtypes, the tumor microenvironment, and treatment sensitivity. Results Using the TCGA pan-cancer data, researchers looked at and examined KMT2 expression patterns and their links to patient survival and the tumor microenvironment in 33 cancer types. The expression of the KMT2 family changes significantly across and within cancer types, indicating significant inter- and intracancer heterogeneity. Patients' overall survival was often linked to the expression of KMT2 family members. However, the direction of the link differed depending on the KMT2 isoform and cancer type studied. Notably, in all cancer types examined, nearly all KMT2 family members were substantially linked with overall survival in patients with renal clear cell carcinoma (KIRC). Furthermore, all KMT2 genes have a strong relationship with immune infiltrate subtypes, as well as varying degrees of stromal cell infiltration and tumor cell stemness. Finally, we discovered that higher expression of KMT2s, particularly KMT2F and KMT2G, was linked to greater chemotherapeutic sensitivity in several cell lines. Conclusions The necessity to investigate each KMT2 member as a distinct entity inside each particular cancer type is highlighted by our comprehensive investigation of KMT2 gene expression and its relationship with immune infiltrates, tumor microenvironment, and cancer patient outcomes. Our research also confirmed the identification of KMT2 as a potential therapeutic target in cancer, but further laboratory testing is required.

Potential Anti-Metastatic Role of the Novel miR-CT3 in Tumor Angiogenesis and Osteosarcoma Invasion.

Osteosarcoma (OS) is the most common primary bone tumor mainly occurring in young adults and derived from primitive bone-forming mesenchyme. OS develops in an intricate tumor microenvironment (TME) where cellular function regulated by microRNAs (miRNAs) may affect communication between OS cells and the surrounding TME. Therefore, miRNAs are considered potential therapeutic targets in cancer and one of the goals of research is to accurately define a specific signature of a miRNAs, which could reflect the phenotype of a particular tumor, such as OS. Through NGS approach, we previously found a specific molecular profile of miRNAs in OS and discovered 8 novel miRNAs. Among these, we deepen our knowledge on the fifth candidate renamed now miR-CT3. MiR-CT3 expression was low in OS cells when compared with human primary osteoblasts and healthy bone. Through TargetScan, VEGF-A was predicted as a potential biological target of miR-CT3 and luciferase assay confirmed it. We showed that enforced expression of miR-CT3 in two OS cell lines, SAOS-2 and MG-63, reduced expression of VEGF-A mRNA and protein, inhibiting tumor angiogenesis. Enforced expression of miR-CT3 also reduced OS cell migration and invasion as confirmed by soft agar colony formation assay. Interestingly, we found that miR-CT3 behaves inducing the activation of p38 MAP kinase pathway and modulating the epithelial-mesenchymal transition (EMT) proteins, in particular reducing Vimentin expression. Overall, our study highlights the novel role of miR-CT3 in regulating tumor angiogenesis and progression in OS cells, linking also to the modulation of EMT proteins.

Discovery of novel tubulin polymerization inhibitors by utilizing 3D-QSAR, molecular docking and molecular dynamics simulation

Tubulin is a potential therapeutic target for cancer.

The druggability of the ATP binding site of glycogen phosphorylase kinase probed by coumarin analogues

Glycogen phosphorylase kinase (PhK) converts by phosphorylation, the inactive glycogen phosphorylase (GPb) into active GPa in the glycogenolytic pathway. It is a complex enzyme comprising of the catalytic (γ) and three regulatory subunits (α, β, δ) forming a hexadecamer with stoichiometry (αβγδ)4. Several studies have indicated PhK as a promising target for the development of antihyperglycemics as its inhibition blocks glycogenolysis in liver and a potential therapeutic target for cancer against pathological angiogenesis and tumor progression. The identification of compounds that inhibit the kinase through their direct binding to its catalytic site is an effective approach to identify bioactive molecules of therapeutic significance. Towards this, the structure of the N-terminal kinase domain (residues 1–298) of the catalytic γ subunit of PhK (PhKγtrnc) has been determined by X-ray crystallography while staurosporine and indirubin analogues have been characterized as potent inhibitors targeting the ATP binding site. In this study, a series of 38 synthetic analogues of naturally occurring coumarins were screened for inhibition of PhKγtrnc, in vitro, using a photometric assay. The IC50 values of the two most potent compounds were determined for PhKγtrnc and the pharmacologically relevant target, human liver isoform (PHKG2A). Their cellular efficacy and toxicity in HepG2 cells were further assessed ex vivo. Docking experiments and the structural comparison with previously described inhibitors reveal the binding mode of the coumarin scaffold at a no hinge region of the ATP site of PhK and the role of a conserved β3-Lys in binding. The experimental findings provide structural insights with implications to the kinase targeting and drug design.