Regulates Cancer Cell Proliferation Research Articles

PDZK1-interacting protein 1(PDZK1IP1) promotes subcutaneous preadipocyte proliferation in goats

PDZK1-interacting protein 1(PDZK1IP1), also known as MAP17, is encoded by the PDZK1IP1 gene and is a membrane-associated protein. PDZK1IP1 have been proven to be a potent regulator of cancer cell proliferation. However, the role of PDZK1IP1 in regulating goat subcutaneous preadipocyte proliferation is unknown. Here, we cloned the full-length coding sequence of PDZK1IP1 gene, investigated the potential functional of PDZK1IP1 in goat subcutaneous preadipocyte proliferation by gaining or losing function in vitro. Our results indicated that goat PDZK1IP1 gene consists of 345 bp, encoding a protein of 114 amino acids containing a typical PDZK1IP1 (MAP17) super family domain. Overexpression of PDZK1IP1 significantly increased the number of EdU-positive cells and cell viability, and also upregulated mRNA expression of cell proliferation-associated genes including CCND1 and CDK2 in vitro cultured cells. Conversely, knockdown of PDZK1IP1 mediated by siRNA technique significantly inhibited subcutaneous preadipocyte proliferation and downregulated mRNA expression of cell proliferation-associated genes including CCNE1, CCND1 and CDK2. Collectively, these results suggested that PDZK1IP1 can promote proliferation of goat subcutaneous preadipocyte.

Oncogenic Role of ADAM32 in Hepatoblastoma: A Potential Molecular Target for Therapy.

Simple SummaryHepatoblastoma (HBL) is a rare hepatic malignancy occurring mainly in early childhood. Although recently developed treatment regimens have improved prognosis, many refractory cases still exist, and the anticancer drug cis-diamminedichloroplatinum—cisplatin—primarily used in HBL treatment often induces severe side effects. Therefore, more effective and safer therapies are needed. In this study, we demonstrate that the expression level of ADAM32 is particularly high in HBL tissue samples and is associated with poor prognosis in various cancer types through the regulation of cancer cell proliferation, stemness, migration, invasion, and acquired resistance to chemotherapy. Our results thus indicate that ADAM32 could be a promising candidate therapeutic target molecule, and provide new insights into the molecular mechanisms of HBL carcinogenesis.Outcomes of pediatric hepatoblastoma (HBL) have improved, but refractory cases still occur. More effective and safer drugs are needed that are based on molecular mechanisms. A disintegrin and metalloproteases (ADAMs) are expressed with high frequency in various human carcinomas and play an important role in cancer progression. In this study, we analyzed expression of ADAMs in HBL with a cDNA microarray dataset and found that the expression level of ADAM32 is particularly high. To investigate the role of ADAM32 in cancer, forced expression or knockdown experiments were conducted with HepG2 and HBL primary cells. Colony formation, cell migration and invasion, and cell viability were increased in HepG2 expressing ADAM32, whereas knockdown of ADAM32 induced a decrease in these cellular functions. Quantitative RT-PCR demonstrated an association between ADAM32 expression and the expression of genes related to cancer stem cells and epithelial–mesenchymal transition (EMT), suggesting a role of ADAM32 in cancer stemness and EMT. Furthermore, knockdown of ADAM32 increased cisplatin-induced apoptosis, and this effect was attenuated by a caspase-8 inhibitor, suggesting that ADAM32 plays a role in extrinsic apoptosis signaling. We conclude that ADAM32 plays a crucial role in progression of HBL, so it might be a promising molecular target in anticancer therapy.

Cancer and apoptosis: The apoptotic activity of plant and marine natural products and their potential as targeted cancer therapeutics.

Cancer is a multifactorial, multi-stage disease, including complex cascades of signaling pathways—the cell growth governed by dysregulated and abrupt cell division. Due to the complexity and multi-regulatory cancer progression, cancer is still a challenging disease to treat and survive. The screening of extracts and fractions from plants and marine species might lead to the discovery of more effective compounds for cancer therapeutics. The isolated compounds and reformed analogs were known as future prospective contenders for anti-cancer chemotherapy. For example, Taxol, a potent mitotic inhibitor discovered from Taxus brevifolia, suppresses cell growth and arrest, induces apoptosis, and inhibits proliferation. Similarly, marine sponges show remarkable tumor chemo preventive and chemotherapeutic potential. However, there is limited research to date. Several plants and marine-derived anti-cancer compounds having the property to induce apoptosis have been approved for clinical trials. The anti-cancer activity kills the cell and slows the growth of cancer cells. Among cell death mechanisms, apoptosis induction is a more profound mechanism of cell death triggered by naturally isolated anti-cancer agents. Evading apoptosis is the major hurdle in killing cancer cells, a mechanism mainly regulated as intrinsic and extrinsic. However, it is possible to modify the apoptosis-resistant phenotype of the cell by altering many of these mechanisms. Various extracts and fractions successfully induce apoptosis, cell-cycle modulation, apoptosis, and anti-proliferative activity. Therefore, there is a pressing need to develop new anti-cancer drugs of natural origins to reduce the effects on normal cells. Here, we’ve emphasized the most critical elements: i) A better understanding of cancer progression and development and its origins, ii) Molecular strategies to inhibit the cell proliferation/Carcino-genesis, iii) Critical regulators of cancer cell proliferation and development, iv) Signaling Pathways in Apoptosis: Potential Targets for targeted therapeutics, v) Why Apoptosis induction is mandatory for effective chemotherapy, vi) Plants extracts/fractions as potential apoptotic inducers, vii) Marine extracts as Apoptotic inducers, viii) Marine isolated Targeted compounds as Apoptotic inducers (FDA Approved/treatment Phase). This study provides a potential therapeutic option for cancer, although more clinical studies are needed to verify its efficacy in cancer chemotherapy.

CircRNAs: novel therapeutic targets in multiple myeloma.

Circular RNA (circRNA) is a type of non-coding RNA that has recently attracted the attention of researchers. Multiple myeloma (MM) is a hematological malignancy with a dismal prognosis that indicates a pressing need for better treatment alternatives, particularly in terms of biological indicators. According to recent research findings, the presence of circRNA is also closely related to the incidence and progression of malignant hemopathy. There have been, however, only a few investigations of circRNA in MM. This review will be on the biological properties and functions of circRNA in MM and a discussion of the clinical utility of circRNA in the diagnosis, prognosis, and treatment of MM. CircRNA is involved in gene transcription, translation, and epigenetic modification as well as the regulation of cancer cell proliferation, invasion, and metastasis, and hence, promotes or inhibits the occurrence and progression of MM. Therefore, circRNA holds promise as a potential future MM biomarker.

Abstract 1471: Over-expression of WW domain containing transcription regulator 1 (TAZ/WWTR1) in prostate cancer and its modulation by prostate-derived ETS factor (PDEF)

Abstract Objective: WW domain containing transcription regulator 1 (TAZ/WWTR1), one of the two downstream effectors of the Hippo pathway, is known to regulate cancer cell proliferation, migration and apoptosis by acting as a transcriptional co-activator. Recently, we described altered expression of yes-associated protein (YAP1) (a paralog of TAZ) in prostate cancer. However, the expression and function of TAZ and its regulation in prostate cancer is not well characterized. In the present study, we profiled expression patterns of TAZ in clinical data sets of PCa and evaluated the effects of PDEF on TAZ phosphorylation in prostate cancer (PCa) cells in culture. Material & Method: We analyzed the publicly available PCa datasets through Ualcan and c-Bioportal webservers. We transfected prostate cancer PC3 cells with PDEF or respective vector control. Protein levels of TAZ were analyzed by western blotting. Global changes in gene expression were analyzed using Affymetrix arrays followed by Gene Set Enrichment analysis. Results: Our analysis of publicly available PCa patient data in TCGA dataset, revealed a significant increase in TAZ mRNA levels in prostate cancer tissues as compared to normal prostate tissues (p=4.95E-08). Furthermore, we also found a significant gradual increase in TAZ mRNA expression during disease progression and metastasis. Our analysis of data sets in c-Bio portal revealed that patients with neuroendocrine PCa harbor much higher levels of TAZ mRNA as compared to CRPC phenotype. We also observed a negative correlation between PDEF and TAZ expression in CRPC/NEPC data set. We observed that the PC3 cells transfected with PDEF (PDEF-PC3) showed an increased phospho-TAZ as compared to the respective PC3 vector control (VC-PC3) suggesting that PDEF plays a critical role in modulating TAZ activity an important effector in Hippo signaling. Conclusions: These results provide first direct demonstration of elevated expression of TAZ in PCa, suggesting potential role of TAZ in prostate cancer. We also show for the first time increased TAZ phosphorylation in PCa cells by PDEF. Taken together with our recent work, our data suggest that PDEF modulates Hippo signaling by targeting both YAP1 and TAZ in PCa. Citation Format: Praveen K. Jaiswal, Suman Mohajan, Sweaty Koul, Hari K. Koul. Over-expression of WW domain containing transcription regulator 1 (TAZ/WWTR1) in prostate cancer and its modulation by prostate-derived ETS factor (PDEF) [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 1471.

Abstract 854: The role of protocadherin, FAT2 in breast cancer

Abstract Protocadherins are cell adhesion molecules that belong to the cadherin superfamily. They are novel cadherin like proteins predominantly associated with early development and morphogenesis, cell growth and patterning, cell-cell adhesion, cell motility (including cell invasion and migration). The Fat-protocadherins are derived from an ancestral Drosophila FAT like cadherin and are evolutionarily conserved. They have been primarily implicated in neuronal cell development and cancer. Several studies have implicated protocadherin dysfunction in cancer. Loss of protocadherin expression, chromosome deletion and epigenetic silencing have been implicated in kidney, prostate, colorectal and breast cancer. More recently they have been implicated in gastric tumors and gliomas. Based on these findings, protocadherins are thought to be tumor suppressors and in general seem to regulate cancer cell proliferation, migration and/or apoptosis. However, multiple exceptions have also been observed and individual protocadherin functions seem to be context-dependent, as some can be considered either tumor suppressors or proto-oncogenes according to the type of cancer being examined. The mechanistics of the roles of the protocadherins in neuronal development have been well dissected but most oncological studies have focused on their characterization as potential biomarkers while the molecular signaling pathways through which the protocadherins regulate growth, invasion and metastasis are still poorly understood. For example recent research has shown that FAT1 is repressed in oral cancer owing to homozygous deletion or epigenetic silencing and is preferentially downregulated in invasive breast cancer. On the other hand, FAT1 is upregulated in leukemia and prognosis of preB-ALL patients with FAT1 upregulation is poor. Therefore FAT1 is tumor suppressive or oncogenic in a context-dependent manner, while FAT4 is tumor suppressive. FAT2 is highly expressed in breast cancer and lung squamous cell carcinoma and the elevated expression of FAT2 is correlated with poor patient outcome.Our preliminary research analysis of the TCGA data from the Genomic Data Commons Portal shows that protocadherins FAT4 and FAT1 are among the top dysregulated genes in cancer. We have also determined that FAT2 has higher Copy Number Variation (CNV) gain events than loss events. Given that there is a well-known concordance between CNV and differential gene expression we believe that FAT2 has a paradoxical oncogenic role in breast cancer. Citation Format: Thomas Roache, Megan Sumera, Zalaila Laird, Amrita Datta. The role of protocadherin, FAT2 in breast cancer [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 854.

Abstract 3140: Interleukin-34 regulates tumor immune microenvironment of renal cell carcinoma

Abstract Renal Cell Carcinoma (RCC) is a type of kidney cancer which derives from renal tubular epithelial cells and is responsible for approximately 90-95% of cases in adults. Incidence and prevalence of RCC are rising, and 5-year survival of metastatic disease is close to 10%. The therapy of RCC mainly targets the angiogenic and immunosuppressive tumor microenvironment (TME), but it is rarely curative and drug resistance is almost inevitable. Lack of validated biomarkers and scarce knowledge of the biological processes occurring during RCC progression are main reasons of therapy failure. Using an immunocompetent murine model of RCC, we identified Interleukin-34 (IL34) as potential biomarker of RCC progression, whose expression is associated with advanced tumor stage and reduced survival in RCC patients. In cancer, IL34 was demonstrated to regulate cancer cell proliferation and monocytes survival and differentiation into macrophages. Regarding to RCC, IL34 role in the TME still remains elusive and has never been described. To elucidate the function of IL34 in RCC biology, we undertook different approaches: Gene Ontology enrichment analysis of IL34 co-expressed genes, using the KIRC-TCGA database, which revealed that such genes are involved in different immune system related processes; orthotopic implantation of IL34 over-expressing murine renal cancer cells (i.e. RENCA cell line) in BALB/c mice, where we observed, both in primary tumors and lung metastases, an accumulation of tumor associated macrophages (TAM) expressing M2-type macrophage markers (e.g. Cd206 and Cd163). Subsequently, to deeply investigate how IL34 can finely tune the tumor immune microenvironment of RCC, we also employed an experiment of Single Nuclei Sequencing using murine samples over-expressing IL34 (or control empty vector). Briefly, RENCA cancer cells were implanted in BALB/c mice using two different injection modalities: orthotopic implantation in the kidney, to generate primary tumors; 2) tail vein injection, for lung metastases formation. After tumor or metastases formation, samples were snap-frozen in liquid nitrogen and processed for cDNA library preparation for next generation sequencing. Our project aims to elucidate how IL34 can be implicated in the regulation of TME in RCC and, in particular, of the phenotype of the accumulated TAM. As TAM are known to promote cancer progression by enhancing tumor angiogenesis and immunosuppression, the study of IL34 role in the TME can reveal novel paradigms in RCC biology, and may be fundamental to improve the current therapy (e.g. using drugs targeting IL34 activity). Citation Format: Andrea Emanuelli, Wilfried Souleyreau, Tiffanie Chouleur, Marie-Alix Derieppe, Andreas Bikfalvi. Interleukin-34 regulates tumor immune microenvironment of renal cell carcinoma [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 3140.

RASAL2 regulates the cell cycle and cyclin D1 expression through PI3K/AKT signalling in prostate tumorigenesis

Prostate cancer (PCa) growth and progression are uniquely dependent on androgens, making the androgen receptor pathway a prime target for therapy; however, cancer progression to androgen independence leads to treatment failure and poor prognosis. In recent years, alternative therapeutic pathways for PCa have been extensively explored, such as the PTEN/PI3K/AKT pathway, cell cycle, and DNA repair. In the present study, we discovered that RASAL2, a RAS-GTPase-activating protein, acted as an oncogene to regulate cancer cell proliferation and the cell cycle and contributed to tumorigenesis via the PI3K/AKT/cyclin D1 pathway. First, RASAL2 expression was higher in PCa tumour and metastatic lymph node tissues than in matched adjacent nontumor tissues and was associated with higher PCa tumour stage, Gleason score and poorer prognosis. Mechanistically, we found that RASAL2 promoted tumour cell proliferation, the transition from G1 to S phase in vitro and tumour growth in vivo. Furthermore, we demonstrated that RASAL2 facilitated phosphorylation of AKT, which in turn increased the expression of cyclin D1 encoded by the CCND1 gene. In addition, there was a positive correlation between the expression of RASAL2 and cyclin D1 in subcutaneous xenografts and clinical specimens. Taken together, these findings indicate that RASAL2 plays an oncogenic role in prostate cancer and may promote PCa tumorigenesis through PI3K/AKT signalling and cyclin D1 expression.

SIK2 inhibition enhances PARP inhibitor activity synergistically in ovarian and triple-negative breast cancers.

Poly(ADP-ribose) polymerase inhibitors (PARP inhibitors) have had an increasing role in the treatment of ovarian and breast cancers. PARP inhibitors are selectively active in cells with homologous recombination DNA repair deficiency caused by mutations in BRCA1/2 and other DNA repair pathway genes. Cancers with homologous recombination DNA repair proficiency respond poorly to PARP inhibitors. Cancers that initially respond to PARP inhibitors eventually develop drug resistance. We have identified salt-inducible kinase 2 (SIK2) inhibitors, ARN3236 and ARN3261, which decreased DNA double-strand break (DSB) repair functions and produced synthetic lethality with multiple PARP inhibitors in both homologous recombination DNA repair deficiency and proficiency cancer cells. SIK2 is required for centrosome splitting and PI3K activation and regulates cancer cell proliferation, metastasis, and sensitivity to chemotherapy. Here, we showed that SIK2 inhibitors sensitized ovarian and triple-negative breast cancer (TNBC) cells and xenografts to PARP inhibitors. SIK2 inhibitors decreased PARP enzyme activity and phosphorylation of class-IIa histone deacetylases (HDAC4/5/7). Furthermore, SIK2 inhibitors abolished class-IIa HDAC4/5/7–associated transcriptional activity of myocyte enhancer factor-2D (MEF2D), decreasing MEF2D binding to regulatory regions with high chromatin accessibility in FANCD2, EXO1, and XRCC4 genes, resulting in repression of their functions in the DNA DSB repair pathway. The combination of PARP inhibitors and SIK2 inhibitors provides a therapeutic strategy to enhance PARP inhibitor sensitivity for ovarian cancer and TNBC.

Multi-Omics Analysis of MCM2 as a Promising Biomarker in Pan-Cancer.

Minichromosome maintenance 2 (MCM2) is a member of the minichromosomal maintenance family of proteins that mainly regulates DNA replication and the cell cycle and is involved in regulating cancer cell proliferation in various cancers. Previous studies have reported that MCM2 plays a pivotal role in cell proliferation and cancer development. However, few articles have systematically reported the pathogenic roles of MCM2 across cancers. Therefore, the present pan-cancer study was conducted. Various computational tools were used to investigate the MCM2 expression level, genetic mutation rate, and regulating mechanism, immune infiltration, tumor diagnosis and prognosis, therapeutic response and drug sensitivity of various cancers. The expression and function of MCM2 were examined by Western blotting and CCK-8 assays. MCM2 was significantly upregulated in almost all cancers and cancer subtypes in The Cancer Genome Atlas and was closely associated with tumor mutation burden, tumor stage, and immune therapy response. Upregulation of MCM2 expression may be correlated with a high level of alterations rate. MCM2 expression was associated with the infiltration of various immune cells and molecules and markedly associated with a poor prognosis. Western blotting and CCK-8 assays revealed that MCM2 expression was significantly upregulated in melanoma cell lines. Our results also suggested that MCM2 promotes cell proliferation in vitro by activating cell proliferation pathways such as the Akt signaling pathways. This study explored the oncogenic role of MCM2 across cancers, provided data on the underlying mechanisms of these cancers for further research and demonstrated that MCM2 may be a promising target for cancer immunotherapy.

Translation initiation factor eIF3a regulates glucose metabolism and cell proliferation via promoting small GTPase Rheb synthesis and AMPK activation

Eukaryotic translation initiation factor 3 subunit A (eIF3a), the largest subunit of the eIF3 complex, has been shown to be overexpressed in malignant cancer cells, potentially making it a proto-oncogene. eIF3a overexpression can drive cancer cell proliferation but contributes to better prognosis. While its contribution to prognosis was previously shown to be due to its function in suppressing synthesis of DNA damage repair proteins, it remains unclear how eIF3a regulates cancer cell proliferation. In this study, we show using genetic approaches that eIF3a controls cell proliferation by regulating glucose metabolism via the phosphorylation and activation of AMP-activated protein kinase alpha (AMPKα) at Thr172 in its kinase activation loop. We demonstrate that eIF3a regulates AMPK activation mainly by controlling synthesis of the small GTPase Rheb, largely independent of the well-known AMPK upstream liver kinase B1 and Ca2+/calmodulin-dependent protein kinase kinase 2, and also independent of mammalian target of rapamycin signaling and glucose levels. Our findings suggest that glucose metabolism in and proliferation of cancer cells may be translationally regulated via a novel eIF3a–Rheb–AMPK signaling axis.

A Substance P (SP)/Neurokinin-1 Receptor Axis Promotes Perineural Invasion of Pancreatic Cancer and Is Affected by lncRNA LOC389641.

Perineural invasion (PNI) is considered to be a main reason for the poor prognosis of pancreatic cancer. In the present study, we analyzed the roles of substance P (SP)/neurokinin-1 receptor (NK-1R) and lncRNA LOC389641 in pancreatic cancer PNI. Pancreatic cancer cell lines BxPC-3 and MIAPaCa-2 were cocultured with SH-SY5Y cells and then stimulated with SP to simulate the in vivo influence of ganglia on pancreatic cancer. The BxPC-3 and MIAPaCa-2 cells were transfected with a neurokinin-1 receptor (NK-1R) overexpression vector, NK-1R silencing vector, LOC389641 overexpression vector, or LOC389641 silencing vector, respectively. The proliferative abilities of BxPC-3 and MIAPaCa-2 cells were assessed using the cell counting kit-8 and 5-ethynyl-2′-deoxyuridine (EdU) assays. Wound-healing and Transwell assays were performed to determine the migration and invasion abilities of the cells. When SP was added to the coculture system, it positively regulated cancer cell proliferation, migration, and PNI and significantly activated the NK-1R/Akt/NF-κB signaling pathway. Incubation with 100 nmol/L SP for 24 h was selected as the optimal condition for treatment. The activated NK-1R positively regulated the proliferation, migration, and invasion of pancreatic cancer cells. However, the levels of lncRNA LOC389641 and tumor necrosis factor receptor SF10A (TNFRSF10A) mRNA in BxPC-3 and MIAPaCa-2 cells were not affected by SP treatment. Overexpression or silencing of LOC389641 changed the effect of SP stimulation on pancreatic cancer PNI. When taken together, these results revealed that SP/NK-1R and LOC389641 promoted the progression of pancreatic cancer PNI. Moreover, we found that pancreatic cancer PNI promoted by the SP/NK-1R axis could be blocked by the TNFRSF10A/NF-κB pathway mediated by LOC389641.

Promising natural lysine specific demethylase 1 inhibitors for cancer treatment: advances and outlooks.

Lysine specific demethylase 1 (LSD1), a transcriptional corepressor or coactivator that serves as a demethylase of histone 3 lysine 4 and 9, has become a potential therapeutic target for cancer therapy. LSD1 mediates many cellular signaling pathways and regulates cancer cell proliferation, invasion, migration, and differentiation. Recent research has focused on the exploration of its pharmacological inhibitors. Natural products are a major source of compounds with abundant scaffold diversity and structural complexity, which have made a major contribution to drug discovery, particularly anticancer agents. In this review, we briefly highlight recent advances in natural LSD1 inhibitors over the past decade. We present a comprehensive review on their discovery and identification process, natural plant sources, chemical structures, anticancer effects, and structure-activity relationships, and finally provide our perspective on the development of novel natural LSD1 inhibitors for cancer therapy.

AFAP1-AS1/Hsa-miR-15a-5p/Bcl-2 Axis is a Potential Regulator of Cancer Cell Proliferation and Apoptosis in Gallbladder Carcinoma

Objective Gallbladder carcinoma (GBC) is a common malignancy of the biliary tract that, with late diagnosis, is often fatal. A better understanding of the underlying molecular mechanisms may facilitate targeted therapy for GBC. Therefore, this study aimed to investigate whether long non-coding RNA AFAP1-AS1 regulates GBC cell proliferation and apoptosis through hsa-miR-15a-5p. Methods SGC-996 and NOZ cell lines were transfected with an hsa-mR-15a-5p inhibitor or si-AFAP1-AS1, and GBC cell proliferation and apoptosis were measured. The expression levels of AFAP1-AS1, hsa-miR-15a-5p, apoptosis-related proteins, and bcl-2 were assessed. The dual-luciferase reporter assay was used to determine the binding between AFAP1-AS1 and hsa-miR-15a-5p or between hsa-miR-15a-5p and bcl-1. Results In SGC-996 and NOZ cells, AFAP1-AS1 was significantly expressed and hsa-miR-15a-5p was modestly expressed. Transfection of the hsa-miR-15a-5p inhibitor elevated proliferation of SGC-996 and NOZ cells and decreased apoptosis, whereas transfection of si-AFAP1-AS1 reduced the proliferation rate and increased apoptosis. In addition, AFAP1-AS1 bound hsa-miR-15a-5p and hsa-miR-15a-5p targeted bcl-2. Increased bcl-2 expression was observed in the GBC cells. AFAP1-AS1 may regulate GBC cell proliferation and apoptosis via has-miR-15a-5p to mediate bcl-2 expression. Conclusion The AFAP1-AS1/hsa-miR-15a-5p/bcl-2 axis regulates GBC cell proliferation and apoptosis, providing potential guidance for the clinical treatment of GBC.

Ca2+/Calmodulin-Dependent Protein Kinase II Inhibits Hepatitis B Virus Replication from cccDNA via AMPK Activation and AKT/mTOR Suppression.

Ca2+/calmodulin-dependent protein kinase II (CaMKII), which is involved in the calcium signaling pathway, is an important regulator of cancer cell proliferation, motility, growth, and metastasis. The effects of CaMKII on hepatitis B virus (HBV) replication have never been evaluated. Here, we found that phosphorylated, active CaMKII is reduced during HBV replication. Similar to other members of the AMPK/AKT/mTOR signaling pathway associated with HBV replication, CaMKII, which is associated with this pathway, was found to be a novel regulator of HBV replication. Overexpression of CaMKII reduced the expression of covalently closed circular DNA (cccDNA), HBV RNAs, and replicative intermediate (RI) DNAs while activating AMPK and inhibiting the AKT/mTOR signaling pathway. Findings in HBx-deficient mutant-transfected HepG2 cells showed that the CaMKII-mediated AMPK/AKT/mTOR signaling pathway was independent of HBx. Moreover, AMPK overexpression reduced HBV cccDNA, RNAs, and RI DNAs through CaMKII activation. Although AMPK acts downstream of CaMKII, AMPK overexpression altered CaMKII phosphorylation, suggesting that CaMKII and AMPK form a positive feedback loop. These results demonstrate that HBV replication suppresses CaMKII activity, and that CaMKII upregulation suppresses HBV replication from cccDNA via AMPK and the AKT/mTOR signaling pathway. Thus, activation or overexpression of CaMKII may be a new therapeutic target against HBV infection.

The Chemokine System in Oncogenic Pathways Driven by Viruses: Perspectives for Cancer Immunotherapy.

Simple SummaryOncoviruses are viruses with oncogenic potential, responsible for almost 20% of human cancers worldwide. They are from various families, some of which belong to the microbial communities that inhabit several sites in the body of healthy humans. As a result, they most often establish latent infections controlled by the arsenal of human host responses that include the chemokine system playing key roles at the interface between tissue homeostasis and immune surveillance. Yet, chemokines and their receptors also contribute to oncogenic processes as they are targeted by the virus-induced deregulations of host responses and/or directly encoded by viruses. Thus, the chemokine system offers a strong rationale for therapeutic options, some few already approved or in trials, and future ones that we are discussing in view of the pharmacological approaches targeting the different functions of chemokines operating in both cancer cells and the tumor microenvironment.Chemokines interact with glycosaminoglycans of the extracellular matrix and activate heptahelical cellular receptors that mainly consist of G Protein-Coupled Receptors and a few atypical receptors also with decoy activity. They are well-described targets of oncogenic pathways and key players in cancer development, invasiveness, and metastasis acting both at the level of cancer cells and cells of the tumor microenvironment. Hence, they can regulate cancer cell proliferation and survival and promote immune or endothelial cell migration into the tumor microenvironment. Additionally, oncogenic viruses display the potential of jeopardizing the chemokine system by encoding mimics of chemokines and receptors as well as several products such as oncogenic proteins or microRNAs that deregulate their human host transcriptome. Conversely, the chemokine system participates in the host responses that control the virus life cycle, knowing that most oncoviruses establish asymptomatic latent infections. Therefore, the deregulated expression and function of chemokines and receptors as a consequence of acquired or inherited mutations could bias oncovirus infection toward pro-oncogenic pathways. We here review these different processes and discuss the anticancer therapeutic potential of targeting chemokine availability or receptor activation, from signaling to decoy-associated functions, in combination with immunotherapies.

Over-Expression and Prognostic Significance of FATP5, as a New Biomarker, in Colorectal Carcinoma.

Background: Fatty acid transporters (FATPs) family play an important role in the uptake and metabolism regulation of long-chain fatty acids, which influence the occurrence and developing of multiple tumors. Fatty acid transporter 5(FATP5), a member of FATPs family, participates in fatty acid transport and lipid metabolism and is related to tumor development, whose mechanism in colorectal cancer (CRC) remains unclear. Methods: In this study, we comprehensively utilized a range of relevant bioinformatic tools along with multiple databases to analyze the expression of FATPs family and investigate the biological function and prognostic value of FATP5 in CRC. Besides, cell proliferation and cell cycle distribution analysis, western blotting and immunohistochemistry (IHC) further validated the conclusion of bioinformatics analysis. Results: FATP5 is the only member of FATPs family which was overexpressed in CRC. In the survival analysis based on the GSE39582 databases, the low expression of FATP5 predicts poor prognosis in CRC. Similar results were also observed in GSE17536, GSE28814 and TCGA colon cohorts. The potential function of DNA methylation regulated the abnormal expression of FATP5 in CRC. In addition, enrichment analysis indicated that FATP5 also participates in the regulation of cell cycle. Furthermore, Gene Set Enrichment Analysis (GSEA) showed a strong negative correlation between FATP5 and cell growth, implying that it may participate in regulating cancer cell proliferation by the regulation of cell cycle G2/M transition. At last, we identified that FATP5 was overexpressed in colorectal carcinoma tissues through immunohistochemistry staining, and played an important role in cell cycle by cell proliferation and cell cycle distribution analysis. Conclusion: This study suggested that FATP5 was overexpression in colorectal carcinoma and predicted favorable prognosis, indicating it as a novel appealing prognostic marker for CRC.

Determining the Anticancer Activity of Sphingosine Kinase Inhibitors Containing Heteroatoms in Their Tail Structure.

Sphingosine kinase (SK) enzyme, a central player of sphingolipid rheostat, catalyzes the phosphorylation of sphingosine to the bioactive lipid mediator sphingosine 1 phosphate (S1P), which regulates cancer cell proliferation, migration, differentiation, and angiogenesis through its extracellular five G protein-coupled S1P receptors (S1PR1–5). Recently, several research studies on SK inhibitors have taken place in order use them for the development of novel anticancer-targeted therapy. In this study, we designed and synthesized analog derivatives of known SK1 inhibitors, namely RB005 and PF-543, by introducing heteroatoms at their tail structure, as well as investigated their anticancer activities and pharmacokinetic parameters in vitro. Compounds 1–20 of RB005 and PF-543 derivatives containing an aliphatic chain or a tail structure of benzenesulfonyl were synthesized. All compounds of set 1 (1–10) effectively reduced cell viability in both HT29 and HCT116 cells, whereas set 2 derivatives (11–20) showed poor anticancer effect. Compound 10, having the highest cytotoxic effect (48 h, HT29 IC50 = 6.223 µM, HCT116 IC50 = 8.694 µM), induced HT29 and HCT116 cell death in a concentration-dependent manner through the mitochondrial apoptotic pathway, which was demonstrated by increased annexin V-FITC level, and increased apoptotic marker cleaved caspase-3 and cleaved PARP. Compound 10 inhibited SK1 by 20%, and, thus, the S1P level decreased by 42%. Unlike the apoptosis efficacy, the SK1 inhibitory effect and selectivity of the PF-543 derivative were superior to that of the RB005 analog. As a result, compounds with an aliphatic chain tail exhibited stronger apoptotic effects. However, this ability was not proportional to the degree of SK inhibition. Compound 10 increased the protein phosphatase 2A (PP2A) activity (1.73 fold) similar to FTY720 (1.65 fold) and RB005 (1.59 fold), whereas compounds 11 and 13 had no effect on PP2A activation. Since the PP2A activity increased in compounds with an aliphatic chain tail, it can be suggested that PP2A activation has an important effect on anticancer and SK inhibitory activities.

RBMS2 Chemosensitizes Breast Cancer Cells to Doxorubicin by Regulating BMF Expression.

Chemoresistance is closely related to the therapeutic effect and prognosis in breast cancer patients. Increasing evidences demonstrated that RNA binding proteins (RBPs) have notable roles in regulating cancer cell proliferation, metastasis and chemotherapeutic sensitivity. RNA binding motif single stranded interacting protein 2 (RBMS2), an RBP, has been considered to be a tumor suppressor in several cancers. However, its role of doxorubicin sensitivity in breast cancer patients has not yet been fully revealed. Here, we performed doxorubicin cytotoxicity assay, flow cytometry and mouse xenograft model to examine the influence of RBMS2 on doxorubicin sensitization in vitro and in vivo. RIP assay and dual-luciferase reporter assay were performed to explore the relationship between RBMS2 and BMF. Our data demonstrated that upregulation of RBMS2 in breast cancer cells could enhance sensitivity to doxorubicin and promote apoptosis in the presence of doxorubicin, while inhibition of RBMS2 showed an opposite trend. Moreover, this chemosensitizing effect of RBMS2 could be reversed by the inhibition of Bcl-2 modifying factor (BMF). RBMS2 positively regulated BMF expression and increased BMF-induced expression of (cleaved) caspase 3, (cleaved) caspase 9 and poly (ADP-Ribose) polymerase (PARP). These results uncovered a novel mechanism for RBMS2 in the sensibilization of doxorubicin, suggesting that RBMS2 may act as a potential therapeutic target for drug-resistant breast cancer.

The Therapeutic Potential of MAPK/ERK Inhibitors in the Treatment of Colorectal Cancer.

The MAPK/ERK signaling pathway regulates cancer cell proliferation, apoptosis, inflammation, angiogenesis, metastasis and drug resistance. Mutations and up-regulation of components of the MAPK/ERK signaling pathway, as well as over-activation of this critical signaling pathway, are frequently observed in colorectal carcinomas. Targeting the MAPK/ERK signaling pathway, using specific pharmacological inhibitors, elicits potent anti-tumor effects, supporting the therapeutic potential of these inhibitors in the treatment of CRC. Several drugs have recently been developed for the inhibition of the MEK/ERK pathway in preclinical and clinical settings, such as MEK162 and MK-2206. MEK1/2 inhibitors demonstrate promising efficacy and anticancer activity for the treatment of this malignancy. This review summarizes the current knowledge on the role of the MAPK/ERK signaling pathway in the pathogenesis of CRC and the potential clinical value of synthetic inhibitors of this pathway in preventing CRC progression for a better understanding, and hence, better management of colorectal cancer.