Cell Lines CaSki Research Articles

Red‐Light Photocatalytic Activation Of Pt(IV) Anticancer Prodrugs Using Methylene Blue

Catalysis‐based approaches offer versatile strategies for activating anticancer prodrugs, potentially allowing precise control over drug release and localization within tumor tissues, while reducing systemic toxicity. In this study, we explore the role of the phenothiazine dye methylene blue (MB+) as a photocatalyst in conjunction with biologically relevant electron donors to facilitate the red‐light conversion of two Pt(IV) complexes, denoted as cis,cis,trans‐[PtCl2(NH3)2(O2CCH2CH2COOH)2] (1) and trans‐[Pt(O2CCH2CH2COOH)21R,2R‐(DACH)(ox)] (2), into cisplatin and oxaliplatin, respectively. Combining spectroscopic techniques (NMR, UV‐Vis, flash photolysis) with computational methods, we reveal that the doubly reduced MB+ (leucomethylene blue, LMB) triggers the reductive elimination of axial ligands in the two Pt(IV) precursors, generating the corresponding Pt(II) anticancer drugs. In vitro experiments conducted on the human cervical cancer cell line CaSki, which harbors multiple copies of the integrated HPV‐16 genome, and on non‐tumoral cells (HaCat) demonstrate that co‐administration with Pt(IV) prodrugs improves MB+'s antiproliferative efficacy in cancer cells, particularly under red light exposure. This enhancement could be attributed to the catalytic production of Pt(II) species within the cellular environment.

RecQ protein-like 4 drives cisplatin chemosensitivity of cervical cancer cells by modulating annexin A2.

Cervical cancer is a common malignant tumor in women with high morbidity and mortality. Chemotherapy drugs such as cisplatin (DDP) are easy to cause chemotherapy resistance and affect the therapeutic effect. Hence, it is critical to design new therapies that can reverse chemotherapy resistance and increase sensitivity to chemotherapy drugs. This study investigated the function of RecQ protein-like 4 (RECQL4) in DDP-resistant cervical cancer cells and its regulatory mechanism. By constructing DDP-resistant Hela and CaSki cell lines, it was found that RECQL4 expression was elevated. RECQL4 knockdown is able to promote apoptosis, DNA damage, and increase the DDP sensitivity in cervical cancer cells. In vivo experiments have demonstrated that knockdown of RECQL4 suppresses tumor growth and promotes tumor apoptosis. Next, we investigated the potential regulatory relationship of RECQL4 to Annexin A2 (ANXA2). The results demonstrated that RECQL4 binds to ANXA2. Knockdown of RECQL4 downregulates the ANXA2 expression via promoting ubiquitination. Furthermore, we also found that ANXA2 overexpression partially abolished the role of RECQL4 knockdown in promoting apoptosis and DNA damage of cervical cancer cells, suggesting that RECQL4 plays a role in DDP sensitivity of cervical cancer cells by mediating ANXA2. In conclusion, the present study suggests that knocking down RECQL4 reduces DDP sensitivity in cervical cancer cells by modulating ANXA2. Targeting RECQL4 therapy may be a new strategy to improve chemosensitivity of cervical cancer cells.

Identification and validation of miR-21 key genes in cervical cancer through an integrated bioinformatics approach

Cervical cancer is one of the most prevalent female reproductive cancers. miR-21 is a multi-target oncomiR that has shown its potential in regulating several cancers including colon, pancreatic, breast, prostate, ovarian, and cervical cancer. However, the signaling network of miR-21 remains underexplored, and only a limited number of miR-21 gene targets in cervical cancer have been reported. In this context, the present study was undertaken to evaluate the role of miR-21 in cervical cancer by combining in silico analysis with in vitro validation in cervical cancer cells. The miR-21 target genes were predicted using four different prediction tools: miRwalk, DIANA, miRDBs, and TargetScan. A total of 113 overlapping target genes, common in at least three of the prediction tools, were shortlisted and subjected to functional enrichment analysis. The analysis predicted that JAK-STAT, MAPK, neurotrophin, and Ras signaling pathways are significantly (p≤0.05) targeted by miR-21. The MCODE plugin identified the potential cluster in the protein-protein interaction network based on the highest degree of connectivity. After GEPIA2 validation of all 20 hub genes, NTF3, LIFR, and IL-6R were shortlisted for validation in cervical cancer cell lines. The results showed that NTF3, LIFR, and IL-6R were significantly upregulated in the miR-21 knockdown CaSki cell lines in 6.27, 1.92 and 1.71 folds (p≤0.01), respectively. Similarly, in HeLa cell lines expression of NTF3, LIFR, and IL-6R were overexpressed in 4,06, 5.65, 2.42 folds (p≤0.001), respectively. confirming the role of miR-21 in regulating the expression of these genes. Additionally, the knockdown of miR-21 significantly inhibited the secretion of matrix metalloproteinases by CaSki cells. These results highlight that miR-21 could be a potential therapeutic target for cervical cancer, although further preclinical and clinical studies are required to validate its role and efficacy.

The Effect of Quercetin on the Expression of miR-21 and miR-34a-5p on HeLa and Ca Ski Cell Lines

Background: Cervical cancer is the fourth most common cancer among women. In recent years, significant progress has been made in its treatment. Quercetin, a polyphenolic compound found in flavonoid-containing plants, is of interest due to its potential therapeutic effects. miR-21 plays a crucial role in cervical tumor metastasis by activating pathways related to invasion and migration, while miR-34a-5p is essential in regulating epithelial-to-mesenchymal transition and preventing increased cell proliferation and migration. The findings of this study could provide insight into the role of quercetin in cancer cells. Objectives: This study aims to investigate the effect of quercetin on the expression levels of miR-21 and miR-34a-5p in HeLa and Ca Ski cervical cancer cell lines. Methods: In this study, HeLa and Ca Ski cells were treated with quercetin. Cell viability and apoptosis were evaluated using the MTT assay and flow cytometry over a 48-hour period. Additionally, the effects of quercetin on the expression levels of miR-21 and miR-34a-5p were analyzed using qRT-PCR. Results: The study demonstrated that quercetin inhibited the viability of HeLa and Ca Ski cells and induced apoptosis in these cells. Quercetin suppressed cell viability with an IC50 of 102.9 μM for HeLa and 304.1 μM for Ca Ski cells after 48 hours. Quercetin down-regulated miR-21 in HeLa and Ca Ski cell lines by 2.5 ± 0.1 (P = 0.045) and 2.0 ± 0.2 (P = 0.016) fold, respectively. Additionally, miR-34a-5p increased by 3.3 ± 0.7 (P = 0.010) and 2.4 ± 0.8 (P = 0.047) fold after exposure to quercetin in HeLa and Ca Ski cell lines, respectively. Conclusions: Our study showed that quercetin has an anti-cervical cancer effect and can be used alongside standard therapies as a promising agent with fewer side effects in cervical cancer treatment.

Prostaglandin E2 suppresses KCNH1 gene expression and inhibits the proliferation of CaSki cervical cells through its four prostanoid PTGER subtypes

The main risk factor for cervical cancer is the persistent infection of high-risk HPV subtypes, notably HPV16. Another contributing factor is proinflammatory prostaglandin E2 (PGE2), a lipid abundantly found in seminal fluid. PGE2, along with its receptors (PTGER1-4), contributes to cancer development; however, its specific role in the proliferation of cervical cancer models with high HPV16 copy numbers remains unclear. In this study, we investigated the effects of PGE2 on the proliferation of CaSki cells, a cell line with a high HPV16 viral load. Surprisingly, PGE2 inhibited CaSki cell proliferation, while it increased the proliferation of SiHa, HeLa, and C-33 A cervical cancer cells. The effect of PGE2 on CaSki cell proliferation was specific, as estradiol increased cell growth. Furthermore, PGE2 suppressed expression and promoter activity of the cervical tumoral marker KCNH1. To discern the specific role of each receptor in cell proliferation, we generated stable CaSki cell lines overexpressing each receptor alongside control cells with an empty vector. Notably, PGE2 significantly inhibited cell proliferation in all stable transfected CaSki cells, suppressing oncogenic KCNH1 expression and its promoter activity. In conclusion, our findings indicate that PGE2 inhibits the proliferation of CaSki cervical cancer cells with a high HPV16 load, at least in part, by suppressing the expression of the oncogenic KCNH1 gene.

Human papillomavirus-16 E6-positive cervical cancer attenuated by potent 2-(4-biphenylyl)-N-(1-ethyl-4-piperidinyl) acetamide second-generation analogs with improved binding affinity.

Human papillomavirus (HPV) infection, particularly HPV16, is a major contributor to the development of cervical cancer. Given the urgent need for novel therapeutic strategies targeting HPV-associated cancers, this study focuses on characterizing second-generation analogs of a lead compound, as a potential inhibitor of HPV16-E6. Protein-ligand docking, Gibbs binding free energy estimation, and molecular dynamics simulations were conducted. HPV16-infected SiHa and CaSki cell lines were used. MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay for proliferation and flow cytometry for target inhibition and apoptosis were employed. Computational and cell proliferation analyses revealed that modifications to E6-855, particularly in the piperidinyl group, enhanced binding affinities against HPV16-E6, with E6-272 demonstrating superior binding properties. Molecular dynamics simulations confirmed the stable binding of E6-272 to HPV16-E6, supported by favorable binding energy estimates. E6-272 inhibited the proliferation of SiHa and CaSki cells with GI50 values of 32.56 and 62.09nM, respectively. The compound reduced HPV16-E6-positive population, while inducing the early and late phase apoptosis in these cells. Structural alterations at the piperidinyl group of E6-855 identified E6-272 as a promising inhibitor of HPV16-E6 with improved efficacy against HPV16-E6. Further experimental validation of E6-272 and its analogs warrant to advance its clinical utility in combating HPV-associated cancers.

Cationic Liposomes Carrying HPV16 E6-siRNA Inhibit the Proliferation, Migration, and Invasion of Cervical Cancer Cells.

The E6 and E7 oncoproteins of high-risk types of human papillomavirus (HR-HPV) are crucial for the development of cervical cancer (CC). Small interfering RNAs (siRNAs) are explored as novel therapies that silence these oncogenes, but their clinical use is hampered by inefficient delivery systems. Modification (pegylation) with polyethylene glycol (PEG) of liposomal siRNA complexes (siRNA lipoplexes) may improve systemic stability. We studied the effect of siRNA targeting HPV16 E6, delivered via cationic liposomes (lipoplexes), on cellular processes in a cervical carcinoma cell line (CaSki) and its potential therapeutic use. Lipoplexes-PEG-HPV16 E6, composed of DOTAP, Chol, DOPE, and DSPE-PEG2000 were prepared. The results showed that pegylation (5% DSPE-PEG2000) provided stable siRNA protection, with a particle size of 86.42 ± 3.19 nm and a complexation efficiency of over 80%; the siRNA remained stable for 30 days. These lipoplexes significantly reduced HPV16 E6 protein levels and restored p53 protein expression, inhibiting carcinogenic processes such as proliferation by 25.74%, migration (95.7%), and cell invasion (97.8%) at concentrations of 20 nM, 200 nM, and 80 nM, respectively. In conclusion, cationic lipoplexes-PEG-HPV16 E6 show promise as siRNA carriers for silencing HPV16 E6 in CC.

Bioinformatics Analysis of Human Papillomavirus 16 Integration in Cervical Cancer: Changes in MAGI-1 Expression in Premalignant Lesions and Invasive Carcinoma.

HPV 16 integration is crucial for the onset and progression of premalignant lesions to invasive squamous cell carcinoma (ISCC) because it promotes the amplification of proto-oncogenes and the silencing of tumor suppressor genes; some of these are proteins with PDZ domains involved in homeostasis and cell polarity. Through a bioinformatics approach based on interaction networks, a group of proteins associated with HPV 16 infection, PDZ domains, and direct physical interaction with E6 and related to different hallmarks of cancer were identified. MAGI-1 was selected to evaluate the expression profile and subcellular localization changes in premalignant lesions and ISCC with HPV 16 in an integrated state in cervical cytology; the profile expression of MAGI-1 diminished according to lesion grade. Surprisingly, in cell lines CaSki and SiHa, the protein localization was cytoplasmic and nuclear. In contrast, in histological samples, a change in subcellular localization from the cytoplasm in low-grade squamous intraepithelial lesions (LSIL) to the nucleus in the high-grade squamous intraepithelial lesion (HSIL) was observed; in in situ carcinomas and ISCC, MAGI-1 expression was absent. In conclusion, MAGI-1 expression could be a potential biomarker for distinguishing those cells with normal morphology but with HPV 16 integrated from those showing morphology-related uterine cervical lesions associated with tumor progression.

PCK1-mediated glycogenolysis facilitates ROS clearance and chemotherapy resistance in cervical cancer stem cells

Cervical cancer, one of the most common gynecological cancers, is primarily caused by human papillomavirus (HPV) infection. The development of resistance to chemotherapy is a significant hurdle in treatment. In this study, we investigated the mechanisms underlying chemoresistance in cervical cancer by focusing on the roles of glycogen metabolism and the pentose phosphate pathway (PPP). We employed the cervical cancer cell lines HCC94 and CaSki by manipulating the expression of key enzymes PCK1, PYGL, and GYS1, which are involved in glycogen metabolism, through siRNA transfection. Our analysis included measuring glycogen levels, intermediates of PPP, NADPH/NADP+ ratio, and the ability of cells to clear reactive oxygen species (ROS) using biochemical assays and liquid chromatography–mass spectrometry (LC–MS). Furthermore, we assessed chemoresistance by evaluating cell viability and tumor growth in NSG mice. Our findings revealed that in drug-resistant tumor stem cells, the enzyme PCK1 enhances the phosphorylation of PYGL, leading to increased glycogen breakdown. This process shifts glucose metabolism towards PPP, generating NADPH. This, in turn, facilitates ROS clearance, promotes cell survival, and contributes to the development of chemoresistance. These insights suggest that targeting aberrant glycogen metabolism or PPP could be a promising strategy for overcoming chemoresistance in cervical cancer. Understanding these molecular mechanisms opens new avenues for the development of more effective treatments for this challenging malignancy.

Identification of exosomal circSLC26A4 as a liquid biopsy marker for cervical cancer.

Circular RNA SLC26A4 (circSLC26A4) functions as an oncogene in the initiation and progression of cervical cancer (CC). However, the clinical role of plasma exosomal circSLC26A4 in CC is poorly known. This study aims to develop an accurate diagnostic method based on circulating exosomal circSLC26A4. In this study, exosomal circSLC26A4 derived from CC cell lines (CaSki, SiHa, and HeLa) and human cervical epithelial cells (HcerEpic) was measured and compared using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Additionally, 56 volunteers, including 18 CC patients, 18 cervical high-grade squamous intraepithelial lesion (HSIL) patients, and 20 healthy volunteers, were enrolled. qRT-PCR was also performed to measure the plasma exosomal circSLC26A4 levels in all participants. The exosomal circSLC26A4 expression level derived from CC cells was significantly elevated compared to it derived from HcerEpic cells. Plasma exosomal circSLC26A4 levels in CC patients were significantly higher than in healthy women and HSIL patients (P < 0.05). In addition, high plasma exosomal circSLC26A4 expression was positively associated with lymph node metastasis and FIGO stage (all P < 0.05). However, no significant correlation was found between plasma exosomal circSLC26A4 expression and age, intravascular cancerous embolus, and perineural invasion (P > 0.05). The high exosomal circSLC26A4 expression is closely related to the occurrence of CC. Plasma exosomal circSLC26A4 can be used as a diagnostic marker for CC.

Identification of transcriptionally-active human papillomavirus integrants through nanopore sequencing reveals viable targets for gene therapy against cervical cancer.

Integration of the human papillomavirus (HPV) genome into the cellular genome is a key event that leads to constitutive expression of viral oncoprotein E6/E7 and drives the progression of cervical cancer. However, HPV integration patterns differ on a case-by-case basis among related malignancies. Next-generation sequencing technologies still face challenges for interrogating HPV integration sites. In this study, utilizing Nanopore long-read sequencing, we identified 452 and 108 potential integration sites from the cervical cancer cell lines (CaSki and HeLa) and five tissue samples, respectively. Based on long Nanopore chimeric reads, we were able to analyze the methylation status of the HPV long control region (LCR), which controls oncogene E6/E7 expression, and to identify transcriptionally-active integrants among the numerous integrants. As a proof of concept, we identified an active HPV integrant in between RUNX2 and CLIC5 on chromosome 6 in the CaSki cell line, which was supported by ATAC-seq, H3K27Ac ChIP-seq, and RNA-seq analysis. Knockout of the active HPV integrant, by the CRISPR/Cas9 system, dramatically crippled cell proliferation and induced cell senescence. In conclusion, identifying transcriptionally-active HPV integrants with Nanopore sequencing can provide viable targets for gene therapy against HPV-associated cancers.

N6-methyladenosine methylation on FSCN1 mediated by METTL14/IGF2BP3 contributes to human papillomavirus type 16-infected cervical squamous cell carcinoma.

Human papillomavirus (HPV) infection has been reported to be associated with N6-methyladenosine (m6A) modification in cancers. However, the underlying mechanism by which m6A methylation participates in HPV-related cervical squamous cell carcinoma (CSCC) remains largely unclear. In this study, we observed that m6A regulators methyltransferase like protein (METTL14) and insulin like growth factor 2 mRNA binding protein 3 (IGF2BP3) were upregulated in HPV-positive CSCC tissues and cell lines, and their high expression predicted poor prognosis for HPV-infected CSCC patients. Cellular functional experiments verified that HPV16 oncogenes E6/E7 upregulated the expression of METTL14 and IGF2BP3 to promote cell proliferation and epithelial mesenchymal transition of CSCC cells. Next, we found that E6/E7 stabilized fascin actin-bundling protein 1 (FSCN1) mRNA and elevated FSCN1 expression in CSCC cells through upregulating METTL14/IGF2BP3-mediated m6A modification, and FSCN1 expression was also validated to be positively associated with worse outcomes of HPV-positive CSCC patients. Finally, HPV16-positive CSCC cell lines SiHa and CaSki were transfected with knockdown vector for E6/E7 or METTL14/IGF2BP3 and overexpressing vector for FSCN1, and functional verification experiments were performed through using MTT assay, flow cytometry, wound healing assay and tumour formation assay. Results indicated that knockdown of E6/E7 or METTL14/IGF2BP3 suppressed cell proliferation, migration and tumorigenesis, and accelerated cell apoptosis of HPV-positive CSCC cells. Their tumour-suppressive effects were abolished through overexpressing FSCN1. Overall, HPV E6/E7 advanced CSCC development through upregulating METTL14/IGF2BP3-mediated FSCN1 m6A modification.

Exploring the Role of E6 and E7 Oncoproteins in Cervical Oncogenesis through MBD2/3-NuRD Complex Chromatin Remodeling.

Cervical cancer is among the highest-ranking types of cancer worldwide, with human papillomavirus (HPV) as the agent driving the malignant process. One aspect of the infection's evolution is given by epigenetic modifications, mainly DNA methylation and chromatin alteration. These processes are guided by several chromatin remodeling complexes, including NuRD. The purpose of this study was to evaluate the genome-wide binding patterns of the NuRD complex components (MBD2 and MBD3) in the presence of active HPV16 E6 and E7 oncogenes and to determine the potential of identified genes through an experimental model to differentiate between cervical precursor lesions, with the aim of establishing their utility as biomarkers. The experimental model was built using the CaSki cell line and shRNA for E6 and E7 HPV16 silencing, ChIP-seq, qRT-PCR, and Western blot analyses. Selected genes' expression was also assessed in patients. Several genes have been identified to exhibit altered transcriptional activity due to the influence of HPV16 E6/E7 viral oncogenes acting through the MBD2/MBD3 NuRD complex, linking them to viral infection and cervical oncogenesis. The impacted genes primarily play roles in governing gene transcription, mRNA processing, and regulation of translation. Understanding these mechanisms offers valuable insights into the process of HPV-induced oncogenesis.

Phytosynthesis of silver nanoparticles using aqueous sandalwood (Santalum album L.) leaf extract: Divergent effects of SW-AgNPs on proliferating plant and cancer cells.

The biogenic approach for the synthesis of metal nanoparticles provides an efficient eco-friendly alternative to chemical synthesis. This study presents a novel route for the biosynthesis of silver nanoparticles using aqueous sandalwood (SW) leaf extract as a source of reducing and capping agents under mild, room temperature synthesis conditions. The bioreduction of Ag+ to Ago nanoparticles (SW-AgNPs) was accompanied by the appearance of brown color, with surface plasmon resonance peak at 340-360 nm. SEM, TEM and AFM imaging confirm SW-AgNP's spherical shape with size range of 10-32 nm. DLS indicates a hydrodynamic size of 49.53 nm with predominant negative Zeta potential, which can contribute to the stability of the nanoparticles. FTIR analysis indicates involvement of sandalwood leaf derived polyphenols, proteins and lipids in the reduction and capping of SW-AgNPs. XRD determines the face-centered-cubic crystalline structure of SW-AgNPs, which is a key factor affecting biological functions of nanoparticles. This study is novel in using cell culture methodologies to evaluate effects of SW-AgNPs on proliferating cells originating from plants and human cancer. Exposure of groundnut calli cells to SW-AgNPs, resulted in enhanced proliferation leading to over 70% higher calli biomass over control, enhanced defense enzyme activities, and secretion of metabolites implicated in biotic stress resistance (Crotonyl isothiocyanate, Butyrolactone, 2-Hydroxy-gamma-butyrolactone, Maltol) and plant cell proliferation (dl-Threitol). MTT and NRU were performed to determine the cytotoxicity of nanoparticles on human cervical cancer cells. SW-AgNPs specifically inhibited cervical cell lines SiHa (IC50-2.65 ppm) and CaSki (IC50-9.49 ppm), indicating potential use in cancer treatment. The opposing effect of SW-AgNPs on cell proliferation of plant calli (enhanced cell proliferation) and human cancer cell lines (inhibition) are both beneficial and point to potential safe application of SW-AgNPs in plant cell culture, agriculture and in cancer treatment.

Synthesis, structural characterization, and quantum chemical study of the 7-acetyl-5-nitrobenzofurans as anticancer agents with antioxidant properties

Synthesis of 7-acetyl-2-aryl-5-nitrobenzofurans 2a–j involved sequential Sonogashira cross-coupling of 2-hydroxy-3-iodo-5-nitroacetophenone with terminal acetylenes and in situ Cacchi-type cycloisomerization of 5-alkynylated intermediates. Hirshfeld's fingerprint diagrams and surface analysis showed varied intermolecular interactions. Additionally, intramolecular interactions were examined using DFT and QTAIM calculations. Benzofuran derivatives were tested for antiproliferative efficacy in vitro against MDA-MB-231 and Caski cell lines. The 1-(5-nitro-2-(p-tolyl)benzofuran-7-yl)ethan-1-one 2h showed promising antiproliferative activity against Caski and MDA-MB-231 cell lines, with IC50 values of 26.96 ± 4.97 µM and 5.13 ± 0.86 µM, respectively, compared to Camptothecin (IC50 = 8.96 ± 0.23 and 24.69 ± 0.26 µM). Derivatives with 2-(4-fluorophenyl)-2c, 2-(4-methoxyphenyl)- 2g, and 2-(3,5-bis(trifluoromethyl)phenyl)-2j groups showed significant antioxidant activity, with Fe-reducing power values of 520.14 ± 1.34 µM, 433.50 ± 1.30 µM, and 466.08 ± 1.91 µM, respectively, compared to ascorbic acid (IC50 = 538.05 µM). The most active molecules that docked with protease (2c, 2g, and 2j) and FKBP12-mTOR (2d, 2h and 2j) active site residues showed significant interactions which were confirmed by Molecular dynamic simulation. ADME investigation indicated drug-like characteristics, safe in silico toxicity, and no carcinogenic or mutagenicity.

Design, synthesis, and biological evaluation of novel benzimidazole derivatives as anti-cervical cancer agents through PI3K/Akt/mTOR pathway and tubulin inhibition

Phosphatidylinositol 3-kinase (PI3K) is one of the most attractive therapeutic targets for cervical cancer treatment. In this study, we designed and synthesized a series of benzimidazole derivatives and evaluated their anti-cervical cancer activity. Compound 4r exhibited strong antiproliferative activity in different cervical cancer cell lines HeLa, SiHa and Ca Ski, and relative lower cytotoxicity to normal hepatic and renal cell lines LO2 and HEK-293t (IC50 values were at 21.08 μM and 23.96 μM respectively). Its IC50 value was at 3.38 μM to the SiHa cells. Further mechanistic studies revealed that 4r induced apoptosis, arrested cell cycle in G2/M phase, suppressed PI3K/Akt/mTOR pathway and inhibit the polymerization of tubulin. Molecular docking study suggested that 4r formed key H-bonds action with PI3Kα (PDB ID:8EXU) and tubulin (PDB ID:1SA0). Zebrafish acute toxicity experiments showed that high concentrations of 4r did not cause death or malformation of zebrafish embryos. All these results demonstrated that 4r would be a promising lead candidate for further development of novel PI3K and tubulin dual inhibitors in cervical cancer treatment.

PAD-mediated citrullination is a novel candidate diagnostic marker and druggable target for HPV-associated cervical cancer.

Citrullination is an emerging post-translational modification catalyzed by peptidyl-arginine deiminases (PADs) that convert peptidyl-arginine into peptidyl-citrulline. In humans, the PAD family consists of five isozymes (PADs 1-4, 6) involved in multiple diseases, including cancer. Given that high-risk (hr) human papillomaviruses (HPVs) are the etiological agents of cervical cancer, in this study, we sought to determine whether PAD-mediated protein citrullination would play a functional role in the HPV-driven transformation of epithelial cells. Here we show that both total protein citrullination and PAD4 expression levels are significantly associated with cervical cancer progression. Specifically, epithelial immunostaining for PAD4 revealed an increasingly higher histoscore from low-grade (CIN1) to high-grade (CIN2, CIN3) cervical intraepithelial neoplasia, and invasive squamous cell carcinoma (SCC) lesions, raising the attractive possibility that PAD4 may be used as tumor staging markers. Furthermore, taking advantage of the epidermoid cervical cancer cell line CaSki, which harbors multiple copies of the integrated HPV16 genome, we show that the expression of E6 and E7 HPV oncoproteins is impaired by treatment with the pharmacological pan-PAD inhibitor BB-Cl-amidine. Consistently, p53 and p21, two targets of HPV oncoproteins, are upregulated by the PAD inhibitor, which undergoes cell growth arrest and apoptosis. Altogether, these findings highlight a novel mechanism by which hrHPVs alter host regulatory pathways involved in cell cycle and survival to gain viral fitness, raising the possibility that PADs may represent an attractive target for developing novel host-targeting antivirals effective in preventing cervical cancer progression.

Tumor cells-derived extracellular vesicles carry circ_0064516 competitively inhibit microRNA-6805-3p and promote cervical cancer angiogenesis and tumor growth

ABSTRACT Background The current study tried to elucidate the regulatory role of tumor cell-derived exosomes (Exos)-circ_0064516 in angiogenesis and growth of cervical cancer. Research design and methods Related cirRNAs and downstream target genes were identified through bioinformatics analysis. Exos were isolated from cervical cancer cell line CaSki, followed by co-cultured with human umbilical vein endothelial cells (HUVECs). Then, the roles of circ_0064516, miR-6805-3p, and MAPK1 in migration and angiogenesis of HUVECs were assayed. Furthermore, xenografted tumors were transplanted into nude mice for in vivo validation. Results In vitro assay validated highly expressed circ_0064516 in cervical cancer cells. Tumor cell-derived Exos carried circ_0064516 to HUVECs. circ_0064516 increased MAPK1 expression by binding to miR-6805-3p, thus enhancing migration and angiogenesis. Exos containing circ_0064516 also promoted tumorigenesis of cervical cancer cells in nude mice. Conclusions We confirmed the oncogenic role of tumor cell-derived Exos carrying circ_0064516 in cervical cancer progression through miR-6805-3p/MAPK1.

Glycolysis Induced by METTL14 Is Essential for Macrophage Phagocytosis and Phenotype in Cervical Cancer.

N 6-methyladenosine (m6A) is the most abundant mRNA modification in mammals and it plays a vital role in various biological processes. However, the roles of m6A on cervical cancer tumorigenesis, especially macrophages infiltrated in the tumor microenvironment of cervical cancer, are still unclear. We analyzed the abnormal m6A methylation in cervical cancer, using CaSki and THP-1 cell lines, that might influence macrophage polarization and/or function in the tumor microenvironment. In addition, C57BL/6J and BALB/c nude mice were used for validation invivo. In this study, m6A methylated RNA immunoprecipitation sequencing analysis revealed the m6A profiles in cervical cancer. Then, we discovered that the high expression of METTL14 (methyltransferase 14, N6-adenosine-methyltransferase subunit) in cervical cancer tissues can promote the proportion of programmed cell death protein 1 (PD-1)-positive tumor-associated macrophages, which have an obstacle to devour tumor cells. Functionally, changes of METTL14 in cervical cancer inhibit the recognition and phagocytosis of macrophages to tumor cells. Mechanistically, the abnormality of METTL14 could target the glycolysis of tumors invivo and vitro. Moreover, lactate acid produced by tumor glycolysis has an important role in the PD-1 expression of tumor-associated macrophages as a proinflammatory and immunosuppressive mediator. In this study, we revealed the effect of glycolysis regulated by METTL14 on the expression of PD-1 and phagocytosis of macrophages, which showed that METTL14 was a potential therapeutic target for treating advanced human cancers.

C-71980262, a novel small molecule against human papilloma virus-16 E6 (HPV-16 E6) with anticancer potency against cervical cancer: A computational guided in vitro approach.

Human papillomavirus-16 E6 (HPV-16 E6) forms a heterodimer complex to up-regulate the degradation of tumor suppressor protein p53 to promote cervical cancer. This study aims to identify a novel small molecule against E6 with anticancer efficacy against HPV-16, a prime high-risk serotype inducer for cervical cancer. Autodock-vina-based high-throughput virtual screening and atomistic molecular dynamic simulations were used for identification of targeted lead molecules. HPV-16 infected SiHa and CaSki cell lines were used to validate the lead compound in vitro. Proliferation of cancer cells was analyzed by MTT assay and flow cytometry was used to analyze target inhibition, apoptosis, and p53. High throughput virtual screening and molecular dynamic simulation identified C-71980262 as a lead candidate that could bind HPV-E6. Atomistic molecular dynamic simulation of E6 bound C-71980262 for 200 ns showed that the predicted ligand binding was stable with minimal energy expenditure, proposing the viability and veracity of the assessed molecule. C-71980262 inhibited the proliferation of SiHa and CaSki cells with GI50 values of 355.70 nM and 505.90 nM, respectively. The compound reduced HPV-16 E6 while inducing early and late-phase apoptosis in these cells. Treatment with C-71980262 increased the p53-positive populations in SiHa and CaSki cells. C-71980262 was identified as a novel lead molecule that could inhibit the HPV-16 E6 and increase p53 in cervical cancer cells. Further in vitro and in vivo validation is warranted to consolidate and corroborate this lead compound against HPV-induced cancer progression.