Expression Of Tumor Suppressor Research Articles

Regulation of m6A (N6-Methyladenosine) methylation modifiers in solid cancers.

Solid cancers constitute a tremendous burden on global healthcare, requiring a deeper understanding of the molecular mechanisms underlying cancer development and progression. Epigenetic changes, notably N6-methyladenosine (m6A) RNA methylation, have emerged as important contributors to the biology of solid tumors in recent years. This epigenetic mark dynamically affects gene expression at the post-transcriptional level and modulates a variety of cellular processes, making it a focus of research in the context of solid tumors. m6A modification patterns are dysregulated in a variety of solid cancers, including ovarian, breast, lung, colorectal, pancreatic, and others. This dysregulated m6A landscape has been shown to induce significant changes in the expression of oncogenes, tumor suppressors, and genes involved in cancer stem cells, metastasis, and treatment resistance. In solid tumors, the interaction of m6A "writers" (e.g., METTL3, METTL14, and others), "erasers" (e.g., ALKBH5, FTO), and "readers" (e.g., members of YTHDF proteins and others) delicately changes the m6A methylome. Targeting m6A regulators as a potential therapeutic method to control gene expression and prevent tumor development seems a novel strategy. To enhance treatment results, advances in this area of research have led to the development of targeted treatments aiming at restoring or altering m6A alteration patterns in solid tumors.

Global Transcriptomic Analysis of Topical Sodium Alginate Protection against Peptic Damage in an In Vitro Model of Treatment-Resistant Gastroesophageal Reflux Disease.

Breakthrough symptoms are thought to occur in roughly half of all gastroesophageal reflux disease (GERD) patients despite maximal acid suppression (proton pump inhibitor, PPI) therapy. Topical alginates have recently been shown to enhance mucosal defense against acid-pepsin insult during GERD. We aimed to examine potential alginate protection of transcriptomic changes in a cell culture model of PPI-recalcitrant GERD. Immortalized normal-derived human esophageal epithelial cells underwent pretreatment with commercial alginate-based anti-reflux medications (Gaviscon Advance or Gaviscon Double Action), a matched-viscosity placebo control, or pH 7.4 buffer (sham) alone for 1 min, followed by exposure to pH 6.0 + pepsin or buffer alone for 3 min. RNA sequencing was conducted, and Ingenuity Pathway Analysis was performed with a false discovery rate of ≤0.01 and absolute fold-change of ≥1.3. Pepsin-acid exposure disrupted gene expressions associated with epithelial barrier function, chromatin structure, carcinogenesis, and inflammation. Alginate formulations demonstrated protection by mitigating these changes and promoting extracellular matrix repair, downregulating proto-oncogenes, and enhancing tumor suppressor expression. These data suggest molecular mechanisms by which alginates provide topical protection against injury during weakly acidic reflux and support a potential role for alginates in the prevention of GERD-related carcinogenesis.

Redox Status and Protein Glutathionylation in Binase-Treated HPV16-Positive SiHa Carcinoma Cells

Human papillomavirus type 16 (HPV16) belongs to viruses of the high-risk type and is associated by overexpression of E6 and E7 oncoproteins, which determine the oncogenic properties of the virus, such as immortalization and malignant transformation of proliferating epithelial cells. The biogenesis of redox-sensitive proteins E6 and E7 at the early stages of viral infection leads to blocking of the cell antioxidant defense system and ubiquintin-dependent degradation of p53 and Rb tumor suppressors. Maintaining high rates of tumor cell proliferation contributes to an increase in the level of reactive oxygen species (ROS) and a shift in the redox balance towards oxidative processes. Reduced glutathione (GSH) provides antioxidant protection to tumor cells through S-glutathionylation of thiol groups of redox-sensitive proteins, which leads to the appearance of multidrug-resistant forms of cancer. In this regard, drugs restoring redox balance and increasing susceptibility to antitumor therapy are of particular importance. We have established that, Bacillus pumilus RNase (binase) modulates the redox-dependent regulatory mechanisms that ensure tumor cell resistance to apoptosis in HPV-16-positive SiHa cells of cervical squamous cell carcinoma,. Binase in nontoxic concentrations initiates a number of pre-apoptogenic changes, i.e., decreases ROS and reduced glutathione (GSH) levels, suppresses the expression of the E6 oncoprotein, activates the expression of the p53 tumor suppressor, and reduces the mitochondrial potential of tumor cells. Binase-induced disruption of the integrity of the mitochondrial membrane is a signal for activation of the mitochondrial apoptosis pathway.

Astragalus polysaccharide ameliorates bone marrow haematopoietic failure in mice with aplastic anaemia via the Hippo/TERT signalling pathway

ObjectiveTo study the effects of astragalus polysaccharide (APS) on aplastic anaemia (AA) in mice through modulation of the upstream and downstream effectors of the Hippo pathway. Further, we investigated the underlying mechanisms of APS in the treatment of AA to provide possible therapeutic strategies and drugs for clinical use. MethodsBALB/c mice were subjected to 4 Gy X-ray irradiation and subsequently injected with lymphocytes from DBA/2 donor mice by using the tail vein to establish an AA mouse model. Next BALB/c mice were randomly divided into five groups: control (untreated), AA (model), and three APS remedy groups - LA (low-dose APS, 200 mg/kg), MA (medium-dose APS, 400 mg/kg), and HA (high-dose APS, 800 mg/kg). The mice were sacrificed after 14 d of continuous gavage with different doses of APS or saline, and the bone marrow, spleen and liver were obtained. The haematopoietic condition, apoptosis levels, and the expression of Large Tumour Suppressor 1/2 (LATS 1/2), transcriptional co-activator of activation (TCA) Yes-associated protein (YesAP), transcriptional enhancer of adherence domain (TEAD) protein, and Telomerase Reverse Transcriptase (TERT), were analysed. ResultsCompared with control mice, mice in the AA group exhibited a reduction in peripheral blood cell counts, a significant decrease in the haematopoietic area, increased adipocyte infiltration, and overall haematopoietic failure, mirroring the clinical presentation of AA; After 14 days of treatment with different doses of APS, the APS-treated group, in comparison to the untreated AA group, showed an increase in peripheral blood cell counts (P < 0.05), an expansionof the haematopoietic area in the bone marrow, restoration of haematopoietic function (P < 0.05), and a marked reduction in adipocyte infiltration within the bone marrow(P < 0.05). Cell infiltration into the bone marrow was also reduced. Further experiments revealed that the expression levels of TERT, LATS 1/2, YAP, and TEAD were elevated in the treated mice (P < 0.05). ConclusionX-ray irradiation combined with T-lymphocyte infusion successfully established an AA mouse model, and APS administration modulated the expression of TERT and the Hippo pathway effectors LATS 1/2, YAP, and TEAD, which are implicated in the pathogenesis of AA. This modulation resulted in the restoration of bone marrow haematopoietic function in AA mice, suggesting APS as a promising therapeutic agent for the treatment of AA.

The up-regulation of SYNCRIP promotes the proliferation and tumorigenesis via DNMT3A/p16 in colorectal cancer

Heterogeneous nuclear ribonucleoproteins (hnRNPs), a group of proteins that control gene expression, have been implicated in many post-transcriptional processes. SYNCRIP (also known as hnRNP Q), a subtype of hnRNPs, has been reported to be involved in mRNA splicing and translation. In addition, the deregulation of SYNCRIP was found in colorectal cancer (CRC). However, the role of SYNCRIP in regulating CRC growth remains largely unknown. Here, we found that SYNCRIP was highly expressed in colorectal cancer by analyzing TCGA and GEPIA database. Furthermore, we confirmed the expression of SYNCRIP expression in CRC tumor and CRC cell lines. Functionally, SYNCRIP depletion using shRNA in CRC cell lines (SW480 and HCT 116) resulted in increased caspase3/7 activity and decreased cell proliferation, as well as migration. Meanwhile, overexpression of SYNCRIP showed opposite results. Mechanistically, SYNCRIP regulated the expression of DNA methyltransferases (DNMT) 3A, but not DNMT1 or DNMT3B, which affected the expression of tumor suppressor, p16. More importantly, our in vivo experiments showed that SYNCRIP depletion significantly inhibited colorectal tumor growth. Taken all together, our results suggest SYNCRIP as a potent therapeutic target in colorectal cancer.

Upregulation of TET2 and Resistance to DNA Methyltransferase (DNMT) Inhibitors in DNMT1-Deleted Cancer Cells.

Ten-eleven-translocation (TET) 2 is a member of the TET family of proteins (TET1-3). DNMT1 gene deletion confers resistance to DNA methyltransferase (DNMT) inhibitors in colorectal, breast, and ovarian cancer cells. Currently, the effect of DNMT1 gene status on TET2 phenotype following DNMT inhibitor treatment is unclear in human malignancies. Human colorectal carcinoma HCT116 cells (DNMT+/+) and their isogenic DNMT1 knockout (DNMT1-/-) counterpart were treated with DNMT inhibitors. Expression of TET2 and tumor suppressor (p16ink4A and p15ink4B) proteins were examined by Western blot. Apoptosis and CDKN2A promoter demethylation following drug treatment were detected by Annexin-V apoptosis assay and methylation-specific PCR. TET2 expression was robustly increased in DNMT1-/- cells by 0.5 µM and 5 µM decitabine and azacitidine treatment. Augmentation of TET2 expression was accompanied by re-expression of p16ink4A and p15ink4B proteins and CDKN2A promoter demethylation. TET2 upregulation and tumor suppressor re-expression were associated with resistance conferred by DNMT1 deletion. Treatment with 5-aza-4'-thio-2'-deoxycytidine at a low 0.5 µM dose only upregulated TET2 and reduced CDKN2A promoter methylation, and re-expression of p16ink4A in DNMT1-/- cells. DNMT inhibitors showed minimal effects on TET2 upregulation and re-expression of tumor suppressor proteins in cells with intact DNMT1. DNMT1 gene deletion made cancer cells prone to TET2 upregulation and activation of tumor suppressor expression upon DNMT inhibitor challenge. TET2 augmentation is concomitant with resistance to DNMT inhibitors in a DNMT1-deleted state.

Targeting of S-phase kinase associated protein 2 stabilized tumor suppressors leading to apoptotic cell death in squamous skin cancer cells

S-phase kinase-associated protein 2 (Skp2) is an F-box protein overexpressed in human cancers and linked with poor prognosis. It triggers cancer pathogenesis, including stemness and drug resistance. In this study, we have explored the potential role of Skp2 targeting in restoring the expression of tumor suppressors in human cutaneous squamous cell carcinoma (cSCC) cells. Our results showed that genetic and pharmacological Skp2 targeting markedly suppressed cSCC cell proliferation, colony growth, spheroid formation, and enhanced sensitization to chemotherapeutic drugs. Further, western blot results demonstrated restoration of tumor suppressor (KLF4) and CDKI (p21) and suppression of vimentin and survivin in Skp2-knocked-down cSCC cells. Importantly, we also explored that Skp2 targeting potentiates apoptosis of cSCC cells through MAPK signaling. Moreover, co-targeting of Skp2 and PI3K/AKT resulted in increased cancer cell death. Interestingly, curcumin, a well-known naturally derived anticancer agent, also inhibits Skp2 expression with concomitant CDKI upregulation. In line, curcumin suppressed cSCC cell growth through ROS-mediated apoptosis, while the use of N-acetyl cysteine (NAC) reversed curcumin-induced cell death. Curcumin treatment also sensitized cSCC cells to conventional anticancer drugs, such as cisplatin and doxorubicin. Altogether, these data suggest that Skp2 targeting restores the functioning of tumor suppressors, inhibits the expression of genes associated with cell proliferation and stemness, and sensitizes cancer cells to anticancer drugs. Thus, genetic, and pharmacological ablation of Skp2 can be an important strategy for attenuating cancer pathogenesis and associated complications in skin squamous cell carcinoma.

Gene expression profiling of p53 and c-myc in HTLV-1 positive blood donors in Congo.

The HTLV-1 infection persists for life, remaining as asymptomatic viral reservoirs in most patients, ensuring the chain of transmission, but around 4% develop adult T-cell leukemia/lymphoma (ATLL). HTLV-1 is an oncogenic retrovirus that transforms CD4+ T lymphocytes and deregulates the lymphoproliferative pathways that contribute to the development of ATLL. To achieve cell transformation, most oncogenic retroviruses use proto-oncogene capture transduction, with proviral integration disrupting the expression of tumor suppressors or proto-oncogenes. We conducted this study on the prevalence of HTLV-1 infection in blood donors to expand the HTLV-1 database, assess the risk of transmission via blood products, as well as evaluate the risk of persistent infection or development of neoplastic diseases in HTLV-1 carriers. This is a cross-sectional study of blood donors of all categories. For this study, 265 blood donors were recruited at the Centre National de Transfusion Sanguine in Brazzaville. After testing for HTLV-1 antibodies by ELISA, proviral DNA was extracted from all ELISA-positive samples for detection by nested PCR, followed by RT qPCR using specific primers p53 and c-myc for gene expression. 20/265 were positive for anti-HTLV-1 antibody, 5 donors were positive for proviral DNA. The prevalence of HTLV-1 was 1.8%. All HTLV-1-positive donors were male (1.8%), with a positive correlation (p = 0.05); the 1.1% of positive donors were regular, with the majority aged between 31 and 45 years (1.5%), and concubine donors were the most frequent (1.1%). All samples showed normal expression of the p53 and c-myc genes. The prevalence, though low, remains a serious problem. No abnormal p53 or c-myc gene expression was detected in HTLV-1-positive donors, which could mean that none of the T lymphocytes in these donors had been transformed by HTLV-1.

Abstract 1103: Molecular signature for treatment-responsive and recurrent Wilms tumors

Abstract Wilms tumor is the most common solid renal malignancy in children. To better understand the biology of Wilms tumors and develop drugs especially against tumors that relapse, we sought to identify mutations in the exome, differential gene expression patterns, and tumor suppressor expression status of Wilms tumors in Kentucky. The Kentucky Cancer Registry (KCR) Virtual Tissue Repository identified 29 cases of Wilms tumor diagnosed between 2015 and 2021 at hospitals across the Commonwealth of Kentucky. The Markey Cancer Center Biospecimen Procurement and Translational Pathology Facility prepared tumor microarrays (TMAs) using Wilms tumor and matching normal tissue cores for immunohistochemistry (IHC) analysis. RNA-Seq analysis performed at the Markey Cancer Center Oncogenomics Facility identified a gene signature that was further validated by IHC and reverse-transcription quantitative-PCR (RT-qPCR). Outcome data provided by KCR indicated that increased expression of an anti-apoptotic protein in the tumor counter-intuitively provided better prognosis and outcome to treatment, indicating that the treatments either directly or indirectly targeted this protein. Loss of function of the tumor suppressor proteins in Par-4/PAWR, WT1 and p53 did not explain the higher expression of the cell survival protein. Our multidisciplinary team approach involves basic science/translational researchers, population scientists, biomedical informaticists, and clinicians and has resulted in well-characterized, Wilms tumor tissue microarrays. The next phase of the study is generating patient derived xenografts (PDXs) for a better understanding of Wilms tumor biology in children. Citation Format: Jieyun Jiang, Derek B. Allison, Ravshan Burikhanov, Saptadwipa Ganguly, Ryan A. Goettl, Jinpeng Liu, Chi Wang, Amanda F. Saltzman, Thomas Tucker, Peter H. Spielmann, Eric B. Durbin, John A. D’Orazio, Vivek M. Rangnekar. Molecular signature for treatment-responsive and recurrent Wilms tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1103.

Heat-killed Prevotella intermedia promotes the progression of oral squamous cell carcinoma by inhibiting the expression of tumor suppressors and affecting the tumor microenvironment

BackgroundOral microbial dysbiosis contributes to the development of oral squamous cell carcinoma (OSCC). Our previous study showed that Prevotella intermedia (P. intermedia) were enriched in the oral mucosal surface, plaque, and saliva of patients with OSCC. Intratumoral microbiome could reshape the immune system and influence the development of various tumors. However, the invasion status of human OSCC tissues by P. intermedia and the pathway through which intratumoral P. intermedia potentiates tumor progression remain unexplored.MethodsP. intermedia in human OSCC or normal tissues was detected by FISH. A mouse OSCC cell line SCC7 was adopted to investigate the effects of heat-killed P. intermedia treatment on cell proliferation, invasion, and cytokine release by using CCK-8 assay, transwell invasion assay and ELISA. Moreover, we established a mouse transplanted tumor model by using SCC7 cells, injected heat-killed P. intermedia into tumor tissues, and investigated the effects of heat-killed P. intermedia on tumor growth, invasion, cytokine levels, immune cell infiltrations, and expression levels by using gross observation, H&E staining, ELISA, immunohistochemistry, mRNA sequencing, and transcriptomic analysis.ResultsOur results indicated that P. intermedia were abundant in OSCC and surrounding muscle tissues. Heat-killed P. intermedia promoted SCC7 cell proliferation, invasion and proinflammatory cytokine secretions, accelerated transplanted tumor growth in mice, exacerbate muscle and perineural invasion of OSCC, elevated the serum levels of IL-17A, IL-6, TNF-α, IFN-γ, and PD-L1, induced Treg cells M2 type macrophages in mouse transplanted tumors. The data of transcriptomic analysis revealed that heat-killed P. intermedia increased the expression levels of inflammatory cytokines and chemokines while reduced the expression levels of some tumor suppressor genes in mouse transplanted tumors. Additionally, IL-17 signaling pathway was upregulated whereas GABAergic system was downregulated by heat-killed P. intermedia treatment.ConclusionsTaken together, our results suggest that P. intermedia could inhibit the expression of tumor suppressors, alter the tumor microenvironment, and promote the progression of OSCC.

Salidroside inhibited the proliferation of gastric cancer cells through up-regulating tumor suppressor miR-1343-3p and down-regulating MAP3K6/MMP24 signal molecules

ABSTRACT Salidroside inhibited the proliferation of cancer cell. Nevertheless, the mechanism has not been completely clarified. The purpose of the study is to explore the mechanisms of salidroside against gastric cancer. To analyze the changes of microRNA (miRNA) in gastric cancer cells under the treatment of salidroside, the miRNA expression was analyzed by using RNA-seq in cancer cells for 24 h after salidroside treatment. The differentially expressed miRNAs were clustered and their target genes were analyzed. Selected miRNA and target mRNA genes were further verified by q-PCR. The expressions of target genes in cancer cells were detected by immunohistochemistry. Cancer cell apoptotic index was significantly increased after salidroside treatment. The proliferation of gastric cancer cells were blocked at S-phase cell cycle. The expression of 44 miRNAs changed differentially after salidroside treatment in cancer cells. Bioinformatic analysis showed that there were 1384 target mRNAs corresponding to the differentially expressed miRNAs. Surprisingly, salidroside significantly up-regulated the expression of tumor suppressor miR-1343-3p, and down-regulated the expression of MAP3K6, STAT3 and MMP24-related genes. Salidroside suppressed the growth of gastric cancer by inducing the cancer cell apoptosis, arresting the cancer cell cycle and down-regulating the related signal transduction pathways. miRNAs are expressed differentially in gastric cancer cells after salidroside treatment, playing important roles in regulating proliferation and metastasis. Salidroside may suppress the growth of gastric cancer by up-regulating the expression of the tumor suppressor miR-1343-3p and down-regulating the expression of MAP3K6 and MMP24 signal molecules.

Targeting histone modifiers in bladder cancer therapy - preclinical and clinical evidence.

Bladder cancer in the most advanced, muscle-invasive stage is lethal, and very limited therapeutic advances have been reported for decades. To date, cisplatin-based chemotherapy remains the first-line therapy for advanced bladder cancer. Late-line options have historically been limited. In the past few years, next-generation sequencing technology has enabled chromatin remodelling gene mutations to be characterized, showing that these alterations are more frequent in urothelial bladder carcinoma than in other cancer types. Histone modifiers have functional roles in tumour progression by modulating the expression of tumour suppressors and oncogenes and, therefore, have been considered as novel drug targets for cancer therapy. The roles of epigenetic reprogramming through histone modifications have been increasingly studied in bladder cancer, and the therapeutic efficacy of targeting those histone modifiers genetically or chemically is being assessed in preclinical studies. Results from preclinical studies in bladder cancer encouraged the investigation of some of these drugs in clinical trials, which yield mixed results. Further understanding of how alterations of histone modification mechanistically contribute to bladder cancer progression, drug resistance and tumour microenvironment remodelling will be required to facilitate clinical application of epigenetic drugs in bladder cancer.

The functional significance of circRNA/miRNA/mRNA interactions as a regulatory network in lung cancer biology

Lung cancer, the leading cause of cancer-related deaths, presents significant challenges to patients due to its poor prognosis. Recent research has increasingly implicated circular RNAs in the development and progression of lung cancer. These circular RNAs have been found to impact various aspects of tumor behavior, including proliferation, metastasis, cell cycle regulation, apoptosis, cancer stem cells, therapy response, and the tumor microenvironment. One of the key mechanisms by which circular RNAs exert their influence is through their ability to act as miRNA sponges, sequestering microRNAs and preventing them from targeting other RNA molecules. Accumulating evidence suggests that circular RNAs can function as competing endogenous RNAs, affecting the expression of target mRNAs by sequestering microRNAs. Dysregulation of competing endogenous RNAs networks involving circular RNAs, microRNAs, and mRNAs leads to the aberrant expression of oncogenes and tumor suppressors involved in lung cancer pathogenesis. Understanding the dynamic interplay and molecular mechanisms among circular RNAs, microRNAs, and mRNAs holds great promise for advancing early diagnosis, personalized therapeutic interventions, and improved patient outcomes in lung cancer. Therefore, this study aims to provide an in-depth exploration of the executive roles of circular RNAs/microRNAs/ mRNAs interactions in lung cancer pathogenesis and their potential utility for diagnosing lung cancer, predicting patient prognosis, and guiding targeted therapies. By offering a comprehensive overview of the dysregulation of the axes as driving factors in lung cancer, we aim to pave the way for their translation into clinical practice in the future.

Abstract C075: Altered RNA splicing causes pancreatic cancer and exposes a therapeutic vulnerability

Abstract Recently we reported that pancreatic ductal adenocarcinomas (PDACs) are exquisitely susceptible to a range of anti-RNA splicing therapies. Thus, altered RNA splicing is a non-mutational dependency of PDACs and represents a novel therapeutic target. However, how these alterations drive tumorigenesis and determine therapeutic responses remains unknown. Using unbiased and quantitative methods to evaluate the effects of all somatic mutations on cancer, we found that mutations in RNA splicing factors SF3B1 and RBM10 (~15% of cases) were among the most significant and mutually exclusive to mutations in p53, suggesting that mutations in these splicing factors act as “second-hit” driver mutations in PDAC. To test this hypothesis, we engineered mice to co-express KrasG12D with either Sf3b1 K700E mutation or Rbm10 loss in acinar cells. Importantly, mice harboring KrasG12D and Sf3b1K700E or Rbm10 loss developed autochthonous PDACs in mice. Mechanistically, we found that both mutant splicing factors, in PDACs from mice and patients, induce alterations in exon processing in common mRNAs. Of these target mRNAs, ~67% were found to be degraded by nonsense-mediated mRNA decay (NMD)- a surveillance process that eliminates mRNAs that harbor sudden stops from splicing alterations. Interestingly, NMD-inducing splicing changes by both SF3B1K700E and RBM10 loss mapped to chromosomes 7 and 11 (chromosomes 17 and 19 in patients, respectively), which are home to several tumor-suppressor genes, including p53. This suggests that mutant splicing factors decrease the expression of specific tumor suppressors by promoting altered RNA splicing and downstream RNA degradation for PDAC pathogenesis. Supporting these findings, it was previously reported that loss of p53 in PDAC, the most common “second-hit” mutation in PDAC, leads to deletions in chromosomes 7 and 11 for PDAC pathogenesis (Nature 2022). Given that 70% of PDACs carry mutations in p53, interestingly however, PDACs with mutant splicing factors have wild-type (WT) p53. We determined that SF3B1K700E and RBM10 loss promote increased degradation of p53 compared to WT counterparts but stabilize p53 protein upon DNA damage and RNA splicing perturbations. Forced expression of gain-of-function mutant p53 in PDACs with either SF3B1K700E or RBM10 loss led to synthetic lethality, explaining the mutual exclusivity found in patient samples (described above). Lastly, splicing factor mutant PDACs are more sensitive to Gemcitabine than 5FU, and combination of Gemcitabine with splicing factor modulator, H3B-8800 (in phase 2 clinical trials) synergized to selectively kill mutant splicing cells. Animal testing of this combination therapy is ongoing using patient-derived organoids implanted in the pancreata of immunocompromised mice. These studies uncover novel driver mutations of PDAC that can bypass the effect of WT p53 and highlights a common mechanism of PDAC pathogenesis that depends on decreased expression of tumor suppressors, irrespective of second-hit mutations, exposing a therapeutic vulnerability to splicing modulators. Citation Format: Natasha Pinto Medici, Diana Martinez Saucedo, Danny Lee, Li-Ting Ku, Robert Tseng, Xinning Shan, Tianyi Chu, Pablo Perez-Piñera, Vincent Cannataro, Jeffrey Townsend, Christine Iacobuzio-Donahue, Marie Robert, Omar Abdel-Wahab, Steven D. Leach, Luisa Escobar-Hoyos. Altered RNA splicing causes pancreatic cancer and exposes a therapeutic vulnerability [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C075.

TSCRE: a comprehensive database for tumor-specific cis-regulatory elements.

Cis-regulatory elements (CREs) and super cis-regulatory elements (SCREs) are non-coding DNA regions which influence the transcription of nearby genes and play critical roles in development. Dysregulated CRE and SCRE activities have been reported to alter the expression of oncogenes and tumor suppressors, thereby regulating cancer hallmarks. To address the strong need for a comprehensive catalogue of dysregulated CREs and SCREs in human cancers, we present TSCRE (http://tscre.zsqylab.com/), an open resource providing tumor-specific and cell type-specific CREs and SCREs derived from the re-analysis of publicly available histone modification profiles. Currently, TSCRE contains 1864941 dysregulated CREs and 68253 dysregulated SCREs identified from 1366 human patient samples spanning 17 different cancer types and 9 histone marks. Over 95% of these elements have been validated in public resources. TSCRE offers comprehensive annotations for each element, including associated genes, expression patterns, clinical prognosis, somatic mutations, transcript factor binding sites, cancer-type specificity, and drug response. Additionally, TSCRE integrates pathway and transcript factor enrichment analyses for each study, enabling in-depth functional and mechanistic investigations. Furthermore, TSCRE provides an interactive interface for users to explore any CRE and SCRE of interest. We believe TSCRE will be a highly valuable platform for the community to discover candidate cancer biomarkers.

Network Pharmacology and Experimental Validation of the Anti-Inflammatory Effect of Tingli Dazao Xiefei Decoction in Acute Lung Injury Treatment.

Tingli Dazao Xiefei Decoction (TDXD) is a Traditional Chinese Medicine (TCM) formula used to treat acute lung injury (ALI). However, the precise mechanism of TDXD in treating ALI remains unclear. We investigated the therapeutic mechanism of TDXD against ALI using a complementary approach combining network pharmacology, molecular docking, and in vitro and in vivo experiments. Potential drug targets of TDXD and relevant target genes associated with ALI were retrieved from Chinese medicines and disease genes databases. Bioinformatics technology was employed to screen potential active ingredients and core targets. Validation experiments were conducted using a lipopolysaccharide (LPS)-induced ALI mouse (C57BL/6J) model, LPS-induced inflammatory RAW264.7 cells, and molecular docking between active compounds of TDXD and potential targets. Network pharmacology suggested that the mechanism of TDXD against ALI involved phosphoinositide 3-kinase (PI3K) / protein kinase B (AKT) / phosphatase and tensin homolog (PTEN) and Janus kinase 2 (JAK2) / signal transducer and activator of transcription 3 (STAT3) pathways. Quercetin, β-sitosterol, kaempferol, isorhamnetin, and L-stepholidine were identified as the main active compounds of TDXD that exerted anti-ALI effects. Molecular docking indicated that these compounds exhibited good binding capabilities (≤ -5kcal/mol) to key targets in PI3K/AKT/PTEN and JAK2/STAT3 signaling pathways. In the animal model, TDXD alleviated injuries and inflammatory responses in lung tissues, accompanied by inhibition of expression of tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), STAT3, and Suppressor of Cytokine Signaling 3 (SOCS3) mRNA, and key proteins in PI3K/AKT/PTEN and JAK2/STAT3 pathways (all P values < 0.05). Cell based experiments showed that TDXD dose-dependently inhibited the expression of essential proteins in PI3K/AKT/PTEN and JAK2/STAT3 pathways (P < 0.05). This study revealed that the mechanism of TDXD in ALI treatment might involve simultaneous regulation of PI3K/AKT/PTEN and JAK2/STAT3 pathways.

Menadione and protocatechuic acid: A drug combination with antitumor effects in murine osteosarcoma cells

Osteosarcoma (OS) is a primary malignant bone tumor that has an abnormal expression of oncogenesis and tumor suppressors and causes dysregulation of various signaling pathways. Thus, novel therapeutic strategies for OS are needed to overcome the resistance of traditional treatments. This study evaluated the cytotoxic and anticancer effects of the association between menadione (MEN) and protocatechuic acid (PCA) in murine OS cells (UMR-106). The concentrations were 3.12 μM of isolated MEN, 500 μM of isolated PCA, and their associations. We performed cell viability assays, morphology modification analysis, cell migration by the wound-healing method, apoptosis by flow cytometry, reactive oxygen species (ROS) production, gene expression of NOX by RT-qPCR, and degradation of MMP-2 and 9 by zymography. Our results showed that the association of MEN+PCA was more effective in OS cells than the compounds alone. The association decreased cell viability, delayed cell migration, and decreased the expression of NOX-2 and ROS. In addition, the MEN+PCA association induced a slight increase in the apoptotic process. In summary, the association can enhance the compound's antitumor effects and establish a higher selectivity for tumor cells, possibly caused by significant mitochondrial damage and antioxidant properties.

S1PR1 regulates ovarian cancer cell senescence through the PDK1-LATS1/2-YAP pathway

Cell senescence deters the activation of various oncogenes. Induction of senescence is, therefore, a potentially effective strategy to interfere with vital processes in tumor cells. Sphingosine-1-phosphate receptor 1 (S1PR1) has been implicated in various cancer types, including ovarian cancer. The mechanism by which S1PR1 regulates ovarian cancer cell senescence is currently elusive. In this study, we demonstrate that S1PR1 was highly expressed in human ovarian cancer tissues and cell lines. S1PR1 deletion inhibited the proliferation and migration of ovarian cancer cells. S1PR1 deletion promoted ovarian cancer cell senescence and sensitized ovarian cancer cells to cisplatin chemotherapy. Exposure of ovarian cancer cells to sphingosine-1-phosphate (S1P) increased the expression of 3-phosphatidylinositol-dependent protein kinase 1 (PDK1), decreased the expression of large tumor suppressor 1/2 (LATS1/2), and induced phosphorylation of Yes-associated protein (p-YAP). Opposite results were obtained in S1PR1 knockout cells following pharmacological inhibition. After silencing LATS1/2 in S1PR1-deficient ovarian cancer cells, senescence was suppressed and S1PR1 expression was increased concomitantly with YAP expression. Transcriptional regulation of S1PR1 by YAP was confirmed by chromatin immunoprecipitation. Accordingly, the S1PR1-PDK1-LATS1/2-YAP pathway regulates ovarian cancer cell senescence and does so through a YAP-mediated feedback loop. S1PR1 constitutes a druggable target for the induction of senescence in ovarian cancer cells. Pharmacological intervention in the S1PR1-PDK1-LATS1/2-YAP signaling axis may augment the efficacy of standard chemotherapy.

Naturally Occurring Phytochemicals to Target Breast Cancer Cell Signaling.

Almost 70% of clinically used antineoplastic drugs are originated from natural products such as plants, marine organism, and microorganisms and some of them are also structurally modified natural products. The naturally occurring drugs may specifically act as inducers of selective cytotoxicity, anti-metastatic, anti-mutagenic, anti-angiogenesis, antioxidant accelerators, apoptosis inducers, autophagy inducers, and cell cycle inhibitors in cancer therapy. Precisely, several reports have demonstrated the involvement of naturally occurring anti-breast cancer drugs in regulating the expression of oncogenic and tumor suppressors associated with carcinogen metabolism and signaling pathways. Anticancer therapies based on nanotechnology have the potential to improve patient outcomes through targeted therapy, improved drug delivery, and combination therapies. This paper has reviewed the current treatment for breast cancer and the potential disadvantages of those therapies, besides the various mechanism used by naturally occurring phytochemicals to induce apoptosis in different types of breast cancer. Along with this, the contribution of nanotechnology in improving the effectiveness of anticancer drugs was also reviewed. With the development of sciences and technologies, phytochemicals derived from natural products are continuously discovered; however, the search for novel natural products as chemoprevention drugs is still ongoing, especially for the advanced stage of breast cancer. Continued research and development in this field hold great promise for advancing cancer care and improving patient outcomes.

Hyperpolarization-activated cyclic nucleotide-gated cation channel 3 promotes HCC development in a female-biased manner

Sex differences in hepatocellular carcinoma (HCC) development are regulated by sex and non-sex chromosomes, sex hormones, and environmental factors. We previously reported that Ncoa5+/- mice develop HCC in a male-biased manner. Here we show that NCOA5 expression is reduced in male patient HCCs while the expression of an NCOA5-interacting tumor suppressor, TIP30, is lower in female HCCs. Tip30 heterozygous deletion does not change HCC incidence in Ncoa5+/- male mice but dramatically increases HCC incidence in Ncoa5+/- female mice, accompanied by hepatic hyperpolarization-activated cyclic nucleotide-gated cation channel 3 (HCN3) overexpression. HCN3 overexpression cooperates with MYC to promote mouse HCC development, whereas Hcn3 knockout preferentially hinders HCC development in female mice. Furthermore, HCN3 amplification and overexpression occur in human HCCs and correlate with a poorer prognosis of patients in a female-biased manner. Our results suggest that TIP30 and NCOA5 protect against female liver oncogenesis and that HCN3 is a female-biased HCC driver.