Proliferation Of Cervical Carcinoma Cells Research Articles

Resveratrol suppresses human cervical carcinoma cell proliferation and elevates apoptosis via the mitochondrial and p53 signaling pathways.

Numerous studies have demonstrated the apoptotic and anti-proliferative effects of resveratrol, a natural polyphenolic phytoalexin, on various cancer cell lines. However, the effects of resveratrol on the regulation of human cervical carcinoma, and the mechanisms underlying these effects, remain to be elucidated. In the present study, the potential mechanisms underlying the effects of resveratrol in HeLa cervical carcinoma cells were investigated. The results revealed that resveratrol inhibited proliferation and induced apoptosis in HeLa human cervical cancer cells in a dose-dependent and time-dependent manner. Resveratrol induced cell shrinkage in HeLa cells and apoptosis accompanied by the activation of caspase-3 and −9. Furthermore, resveratrol upregulated the expression of the pro-apoptotic B-cell lymphoma (Bcl)-2-associated X protein and downregulated the expression of the anti-apoptotic proteins Bcl-2 and Bcl-extra large in HeLa cells. In addition, p53, a protein that is essential for cell survival and cell cycle progression, exhibited elevated expression levels in resveratrol-treated HeLa cells. Therefore, resveratrol may be a promising novel inhibitor of human cervical cancer.

Effects of both folic acid, p16 protein expression and their interaction on progression of cervical cancerization

Objective: To explore the effects of both folic acid, p16 protein expression and their interaction on progression of cervical cancerization. Methods: Participants were pathologically diagnosed new cases, including 80 women with normal cervical (NC), 55 patients with low-grade cervical intraepithelial neoplasia (CINⅠ), 55 patients with high-grade cervical intraepithelial neoplasia (CINⅡ/Ⅲ) and 64 patients with cervical squamous cell carcinoma (SCC). Serum folate levels were detected by microbiological assay method while p16 protein expression levels were measured by Western-blot. In vitro, cervical cancer cell lines C33A (HPV negative) and Caski (HPV16 positive) were treated with different concentrations of folate. Proliferation and apoptosis of cells and the levels of p16 protein expression were measured in groups with different folic acid concentrations. Results: Results showed that the levels of serum folate were (5.96±3.93) ng/ml, (5.08±3.43) ng/ml, (3.92±2.59) ng/ml and (3.18±2.71) ng/ml, and the levels of p16 protein were 0.80±0.32, 1.33±0.52, 1.91±0.77, and 2.09±0.72 in the group of NC, CINⅠ, CINⅡ/Ⅲ and SCC, respectively. However, the levels of serum folate decreased (trend χ2=32.71, P<0.001) and p16 protein expression increased (trend χ2=56.06, P<0.001) gradually along with the severity of cervix lesions. An additive interaction was seen between serum folate deficiency and high expression of p16 protein in the CINⅠ, CINⅡ/Ⅲ and SCC group. Results in vitro showed that, with the increase of folate concentration, the inhibition rate of cell proliferation (C33A: r=0.928, P=0.003; Caski: r=0.962, P=0.001) and the rate on cell apoptosis (C33A: r=0.984, P<0.001; Caski: r=0.986, P<0.001) all increased but the levels of p16 protein expression (C33A: r=-0.817, P=0.025; Caski: r=-0.871, P=0.011) reduced. The proliferation inhibition rate (C33A: r=-0.935, P=0.002; Caski: r=-0.963, P=0.001) and apoptosis rate of cells (C33A: r=-0.844, P=0.017; Caski: r=-0.898, P=0.006) were negatively correlated with the levels of p16 protein expression. Conclusions: Our findings indicated that both serum folate deficiency and high expression of p16 protein could increase the risk of cervical cancer and cervix precancerous lesion, and there was an additive interaction between them. Our findings suggested that folic acid supplementation could reverse the abnormal expression of p16 protein, and effectively promote apoptosis and inhibit proliferation in cervical carcinoma cells.

Dual blocking of PI3K and mTOR signaling by NVP-BEZ235 inhibits proliferation in cervical carcinoma cells and enhances therapeutic response

NVP-BEZ235 is a novel dual PI3K/mTOR inhibitor that shows dramatic effects on many tumors, but its effects on cervical carcinoma cells are largely unknown. In the present study, we investigated the effects of NVP-BEZ235 on the proliferation and invasion of cervical carcinoma cells in vitro and clarified its mechanism of action. In cellular settings with human cervical carcinoma cell lines, this molecule effectively and specifically blocked dysfunctional PI3K/mTOR pathway activation, suppressed cell growth in a time- and concentration-dependent manner, led to G1 cell cycle arrest, and induced apoptosis. NVP-BEZ235 suppressed HeLa cell invasiveness and metastasis by inhibiting the PI3K/Akt/MMP-2 pathway. We further demonstrated that NVP-BEZ235 treatment in combination with cisplatin or carboplatin induced a synergistic anti-tumoral response in cervical carcinoma cells. These findings suggested that NVP-BEZ235 could regulate growth and invasion of cervical carcinoma cells; thus it may provide a potential therapy for cervical carcinoma.

The inhibition of cervical carcinoma cell proliferation and infiltration by IL-37

Interleukin-37 (IL-37) is member 7 of the IL-1 family and inhibits pro-inflammatory factor activities. Cervical carcinoma is a malignant tumor associated with inflammation. The roles of IL-37 in the occurrence and progression of cervical cancer have not been elucidated. This study investigated the roles of IL-37 in the proliferation, survival, invasion, and migration of cervical cancer cells.

Acidic and basic fibroblast growth factor expression levels in cervical cancer and their effects on tumor cell proliferation.

Fibroblast growth factors (FGFs) play important roles in angiogenesis, wound healing, embryonic development, and endocrine signaling pathways. Increasingly, recent studies have reported aberrant FGF expression in various malignancies. However, the involvement of FGFs in cervical carcinoma pathogenesis remains unclear. We aimed to investigate expression of acidic (aFGF) and basic FGF (bFGF) in patients with this disease, and assess their effects on cervical cancer cell proliferation. Twenty cervical cancer patients and 10 cervical intraepithelial neoplasia (CIN) patients were recruited, and 10 cancer-free individuals were included as controls. Reverse transcription-polymerase chain reaction and western blotting were employed to detect FGF mRNA and protein levels, respectively. Furthermore, HeLa cells were treated with FGFs and subjected to thiazolyl blue tetrazolium bromide assays to quantify proliferation. Compared with CIN and normal cervical tissues, aFGF and bFGF mRNA and protein levels were significantly elevated in cervical carcinomas (P < 0.05). CIN tissues exhibited higher expression of these FGFs than normal tissues (P < 0.05). Moreover, their mRNA levels were increased in advanced cancer stages (P < 0.05), although no significant difference was detected between tumors of different differentiation grades in this regard (P > 0.05). HeLa cell proliferation increased in an aFGF- and bFGF-dose-dependent manner (P < 0.05), the latter exerting a more potent proliferative influence, with its effect peaking at 75 ng/mL. aFGF and bFGF were highly expressed in cervical cancer tissues and their levels positively correlated with clinical stage. Both facilitate proliferation of cervical carcinoma cells and are implicated in cancer pathogenesis and progression.

Unexpected inhibition of cervical carcinoma cell proliferation by expression of heat shock transcription factor 1

Unexpected inhibition of cervical carcinoma cell proliferation by expression of heat shock transcription factor 1

MiR-99 inhibits cervical carcinoma cell proliferation by targeting TRIB2

MicroRNAs (miRNAs) have significant roles in cell processes, including proliferation, apoptosis and stress responses. To investigate the involvement of miR-99 in the inhibition of HeLa cell proliferation, an miR-99 gene expression vector (pU6.1/miR-99), which overexpressed miR-99 in HeLa cells after transient transfection, was constructed. The expression of miR-99 was detected by qPCR. Cell proliferation and apoptosis were analyzed by cell viability, proliferation and apoptosis assays, as well as by electron microscopy. The results showed that overexpression of miR-99 in HeLa cells increased the HeLa cell mortality rate. Moreover, miR-99 overexpression was able to markedly inhibit HeLa cell proliferation according to the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cell apoptosis rate was significantly higher in pU6.1/miR-99-treated cells compared with that in the control cultures. Increases in intracellular electron density, as well as the proportion of nuclear plasma, blebbing phenomena and apoptotic bodies were observed in pU6.1/miR-99-treated cells compared with control cultures according to electron microscopy analysis. The Tribbles 2 (TRIB2) 3′-untranslated region was also observed to be targeted by miR-99 and the results further demonstrated that miR-99 was able to negatively regulate TRIB2 expression in HeLa cells The results indicate that miR-99 acts as a tumor suppressor gene in HeLa cells, establishing a theoretical basis for its application in cancer therapeutics.

Long non-coding RNA MEG3 inhibits the proliferation of cervical carcinoma cells through the induction of cell cycle arrest and apoptosis

Cervical cancer remains an important public health problem worldwide. New and effective therapeutic strategies targeting cervical cancer are urgently needed. Long non-coding RNAs (lncRNAs) are newly identified regulators in tumorigenesis and tumor progression. To investigate the role of lncRNA MEG3 in the development of cervical cancer, we examined MEG3 expression in 18 pairs of cervical cancer and matched adjacent non-neoplastic tissues. Real-time quantitative RT-PCR (qRT-PCR) results showed high expression levels of MEG3 in non-neoplastic tissues, but markedly lower levels in cancer tissues. We further investigated whether the restoration of MEG3 expression might affect the proliferation of cervical carcinoma cells. Ectopic expression of MEG3 inhibited the proliferation of human cervical carcinoma cells HeLa and C-33A in vitro. On the other hand, knockdown of MEG3 promoted the growth of well-differentiated cervical carcinoma HCC94 cells. Further investigation into the mechanisms responsible for the growth inhibitory effects revealed that overexpression of MEG3 resulted in the induction of G2/M cell cycle arrest and apoptosis. These results identified an important role of MEG3 in the molecular etiology of cervical cancer and implicated the potential application of MEG3 in cervical cancer therapy.

The microRNA-302-367 cluster suppresses the proliferation of cervical carcinoma cells through the novel target AKT1

The miR-302-367 cluster is specifically expressed in human embryonic stem cells and has been shown to convert human somatic cells into induced pluripotent stem cells. Here, we investigated the role of the miR-302-367 cluster in cervical carcinoma. The cluster was not endogenously expressed in cervical cancer cells, and its ectopic expression did not reprogram the cervical cancer cells to an embryonic stem cell-like state. However, ectopic expression of the miR-302-367 cluster in HeLa and SiHa cervical cancer cells inhibited cell proliferation and tumor formation by blocking the G1/S cell cycle transition. We identified a new cell cycle regulatory pathway in which the miR-302-367 cluster directly down-regulated both cyclin D1 and AKT1 and indirectly up-regulated p27(Kip1) and p21(Cip1), leading to the suppression of cervical cancer cell proliferation. Our findings suggest that the miR-302-367 cluster may be used as a therapeutic reagent for the treatment of cervical carcinoma.

RETRACTED: MicroRNA-19a and -19b regulate cervical carcinoma cell proliferation and invasion by targeting CUL5

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Upon investigation, it was discovered that 4 out of 8 images contain fabrication. Figures 6D, 6E, 8E and 7F have used the same microscopic image for different experimental settings. The Figure represented in 8E is the correct image placement. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Hes1/Hes5 Gene Inhibits Differentiation via Down-Regulating Hash1 and Promotes Proliferation in Cervical Carcinoma Cells

Hairy and enhancer of split 1 (Hes1) and Hes5 are target genes for the mammalian Notch pathway, which are highly expressed in epithelia in the process of embryogenesis or in neural stem cells, inhibit cell differentiation via the Notch-Hes-Hash signaling, and promote the survival of stem cells. Either Hes1 or Hes5 overactivation is likely to affect cell differentiation, thereby resulting in carcinogenesis. We transfected the diced small interference RNA into SiHa cells and detected cell differentiation and proliferation by immunocytochemistry, Western blot, and methyl thiazolyl tetrazolium assay. Knockdown of Hes1 and Hes5 would up-regulate the downstream gene Hash1, but not the upstream gene Notch1 in the Notch-Hes-Hash pathway. After Hes1/Hes5 RNA interference, expression of differentiation-associated proteins (including Nanog, stage-specific embryonic antigen 4, and tumor rejection antigen-1-60) was reduced, and the cell differentiation was promoted; meanwhile, the cell proliferation was inhibited, which was verified by detecting proliferation-associated proteins (eg, Ki-67, proliferating cell nuclear antigen) and methyl thiazolyl tetrazolium assay. Our findings suggest that Hes1/Hes5 gene would inhibit the cell differentiation via down-regulating Hash1 and promote the cell proliferation in cervical carcinoma cells; the cell differentiation and proliferation can be reversed simultaneously by Hes1/Hes5 knockdown using RNA interference.

Expression of the Bric-a-Brac Tramtrack Broad Complex Protein NAC-1 in Cervical Carcinomas Seems to Correlate with Poorer Prognosis

Recent studies have suggested a novel oncogenic role of a bric-a-brac tramtrack broad complex (also known as POZ) domain gene, NAC-1, in ovarian carcinomas. The aim of this study was to clarify the functional role of NAC-1 in human cervical carcinomas. NAC-1 expression in cervical cancer was assessed by immunohistochemistry, and data on clinical variables were collected by retrospective chart review. NAC-1 gene knockdown using small interfering RNA and a NAC-1 gene transfection system were used to asses NAC-1 function in cervical cancer in vivo. Immunohistochemical and gene expression analysis revealed that NAC-1 is significantly overexpressed in cervical adenocarcinomas and adenosquamous carcinomas compared with squamous cell carcinomas. Patients with squamous cell carcinomas positive for NAC-1 expression who received radiotherapy had significantly shorter overall survival than peers whose tumors did not express NAC-1, and multivariate analysis showed that NAC-1 expression was an independent prognostic factor for overall survival after radiotherapy. Overexpressions of the NAC-1 gene stimulated cell proliferation in cervical carcinoma cells of the TCS, CaSki, and HeLa P3 lines, which do not have endogenous NAC-1 expression. NAC-1 gene knockdown inhibited cell growth and induced apoptosis in HeLa, HeLa TG, and ME180 cells, all of which overexpressed NAC-1. Our findings suggest that NAC-1 may play an important role in cervical carcinomas; moreover, these findings provide a rationale for future development of NAC-1-based therapy for cervical carcinomas that overexpress this candidate oncogene.

Downregulation of Sef, an inhibitor of receptor tyrosine kinase signaling, is common to a variety of human carcinomas

Carcinomas are tumors of epithelial origin accounting for over 80% of all human malignancies. A substantial body of evidence implicates oncogenic signaling by receptor tyrosine kinases (RTKs) in carcinoma development. Here we investigated the expression of Sef, a novel inhibitor of RTK signaling, in normal human epithelial tissues and derived malignancies. Human Sef (hSef) was highly expressed in normal epithelial cells of breast, prostate, thyroid gland and the ovarian surface. By comparison, substantial downregulation of hSef expression was observed in the majority of tumors originating from these epithelia. Among 186 primary carcinomas surveyed by RNA in situ hybridization, hSef expression was undetectable in 116 cases including 72/99 (73%) breast, 11/16 (69%) thyroid, 16/31 (52%) prostate and 17/40 (43%) ovarian carcinomas. Moderate reduction of expression was observed in 17/186, and marked reduction in 40/186 tumors. Only 13/186 cases including 12 low-grade and one intermediate grade tumor retained high hSef expression. The association of hSef downregulation and tumor progression was statistically significant (P<0.001). Functionally, ectopic expression of hSef suppressed proliferation of breast carcinoma cells, whereas inhibition of endogenous hSef expression accelerated fibroblast growth factor and epidermal growth factor-dependent proliferation of cervical carcinoma cells. The inhibitory effect of hSef on cell proliferation combined with consistent downregulation in human carcinoma indicates a tumor suppressor-like role for hSef, and implicates loss of hSef expression as a common mechanism in epithelial neoplasia.

Effects of Local Administration of Propolis and Its Polyphenolic Compounds on Tumor Formation and Growth

Many dietary constituents are chemopreventive in animal models, and experiments with cultured cells are revealing various potential mechanisms of action. Compounds classified as blocking agents can prevent, or greatly reduce, initiation of carcinogenesis, or suppressing agents can act on cell proliferation. Caffeic acid (CA) and caffeic acid phenethyl ester (CAPE), members of the polyphenolic compounds, are present in high concentrations in medicinal plants and propolis, a natural beehive product. A water-soluble extract of propolis (WSDP) and two components of propolis, CA and CAPE were investigated for direct antitumor activity in vivo and in vitro. The local presence of CA and CAPE in the tissue caused a significant delay in tumor formation and increased life span 29.30 to 51.73%, respectively. CA and CAPE, but not WSDP, significantly suppressed human HeLa cervical carcinoma cell proliferation in vitro. Based on these results, we postulate that the antitumor activity of polyphenolic compounds includes direct cytotoxic effects on tumor cells.

Role of the retinoblastoma pathway in senescence triggered by repression of the human papillomavirus E7 protein in cervical carcinoma cells.

Repression of the endogenous human papillomavirus (HPV) type 18 E7 gene in HeLa cervical carcinoma cells by the bovine papillomavirus E2 transcription factor activates the retinoblastoma (Rb) pathway and induces cells to undergo senescence. To determine whether activation of the Rb pathway is responsible for senescence in response to HPV18 E7 repression, we tested the ability of wild-type and mutant E7 proteins to affect the activity of the Rb pathway and to modulate senescence in these cells. Enforced expression of the wild-type HPV16 E7 protein prevented Rb activation in response to E2 expression and impaired senescence. Importantly, there was an absolute correlation between the ability of mutant E7 proteins to inactivate the Rb pathway and to inhibit senescence in HeLa cells. Similar results were obtained in HT-3 cervical carcinoma cells. These results provide strong genetic evidence that activation of the Rb pathway is required for senescence in response to E7 repression. Hence, continuous neutralization of the Rb pathway by the E7 protein is required to maintain the proliferation of cervical carcinoma cells. Similarly, our results indicate that activation of the Rb pathway can prevent apoptosis induced by repression of the HPV18 E6 gene in HeLa cells.

Phenylbutyrate inhibits growth of cervical carcinoma cells independent of HPV type and copy number.

Inhibitors of histone deacetylase, such as sodium butyrate, block proliferation of cervical carcinoma cells by inhibiting the G1 to S transition of the cell cycle. The derivative phenylbutyrate (PB), characterized by its higher pharmacological half-life, and its metabolite phenylacetate (PA) were tested for their growth-inhibitory function on cervical cancer cells differing in their HPV type, copy number, and integration sites. Using flow cytometric and Western blot analyses, we show that a 24-h incubation period with PB, but not with PA, was already sufficient to cause a dose-dependent growth arrest by increasing the G1 fraction with a concomitant drop in the S-phase. Consistent with the cell cycle block, only PB, but not PA, induced the cyclin-dependent kinase inhibitors p21(CIP1) and p27(KIP1). The inhibitory effect was not the result of a non-specific cytotoxic effect of PB, since cessation of cellular growth was already completely reversible 5 h after drug removal. Due to its broad growth inhibitory properties on different cervical carcinoma cells in vitro, and its low toxic profile demonstrated in preceding clinical studies, PB may serve as an effective drug in handling pre-cancerous lesions and cervical cancer in patients.

Endogenous Human Papillomavirus E6 and E7 Proteins Differentially Regulate Proliferation, Senescence, and Apoptosis in HeLa Cervical Carcinoma Cells

Cervical cancer cells express high-risk human papillomavirus (HPV) E6 and E7 proteins, and repression of HPV gene expression causes the cells to cease proliferation and undergo senescence. However, it is not known whether both HPV proteins are required to maintain the proliferative state of cervical cancer cells, or whether mutations that accumulate during carcinogenesis eliminate the need for one or the other of them. To address these questions, we used the bovine papillomavirus E2 protein to repress the expression of either the E6 protein or the E7 protein encoded by integrated HPV18 DNA in HeLa cervical carcinoma cells. Repression of the E7 protein activated the Rb pathway but not the p53 pathway and triggered senescence, whereas repression of the E6 protein activated the p53 pathway but not the Rb pathway and triggered both senescence and apoptosis. Telomerase activity, cyclin-dependent kinase activity, and expression of c-myc were markedly inhibited by repression of either E6 or E7. These results demonstrate that continuous expression of both the E6 and the E7 protein is required for optimal proliferation of cervical carcinoma cells and that the two viral proteins exert distinct effects on cell survival and proliferation. Therefore, strategies that inhibit the expression or activity of either viral protein are likely to inhibit the growth of HPV-associated cancers.

Endothelin receptor blockade inhibits the growth of human papillomavirus-associated cervical carcinoma.

Human papillomaviruses (HPVs) are associated with cervical cancer and interact with growth factors that may enhance malignant transformation of cervical carcinoma cells. Endothelin-1 (ET-1) is released from HPV-transfected keratinocytes and induces increased growth response in these cell lines in comparison with normal cells. HPV-positive cancer cells secrete ET-1 and express mRNA for ET-1 and its receptors, whereas HPV-negative carcinoma cell lines express only the ET(B) receptor (ET(B)R) mRNA and do not secrete ET-1. In HPV-positive cancer cells, ET(A)R mediates the ET-1-induced mitogenic effect and sustains the basal growth rate of unstimulated cervical tumour cells. Therefore, ET-1 may be involved in the neoplastic growth of HPV-associated cervical carcinoma, where the increased ET-1 autocrine loop can be targeted for antitumour therapy. In the present work, the action of specific antagonists of ET(A)R (BQ-123 and ABT-627), was analysed in CaSki and C33A cells that are derived from human cervical carcinoma. CaSki cells are HPV-16-positive, produce ET-1 and possess ET(A)R and ET(B)R, whereas the C33A line is HPV-negative, does not secrete ET-1 and has no ET(A)R. In HPV-positive cancer cells ABT-627 strongly inhibited the proliferation induced by ET-1 and substantially reduced the basal growth rate of unstimulated cervical tumour cells, whereas the ET(B)R antagonist had no effect. These results demonstrate that ET-1 participates in the progression of neoplastic growth in HPV-associated carcinoma, in which ET(A)R expression is increased and could be targeted for antitumour therapy. In conclusion, an ET-1 autocrine loop is involved in tumour cell proliferation via ET(A)R, and ABT-627 is effective in controlling proliferation of cervical carcinoma cells.

Growth Suppression of a Cervical Cancer Cell Line (TMCC-1) by the Human Wild-Type p53 Gene

To investigate the effects of human wild-type p53 expression on the proliferation of cervical carcinoma cells, a plasmid, pMO7-hp53, which contains a full-length cDNA of the human wild-type p53 (wt-p53) gene, was transfected into a cell line (TMCC-1) derived from an endocervical type, human papilloma virus-positive adenocarcinoma of the uterine cervix. The exogenous wt-p53 expression induced growth suppression, morphological changes, and loss of anchorage-independent growth of the tumor cells. As the wt-p53 gene apparently plays a negative role in growth regulation of cervical carcinoma cells, this gene may possibly be of some use for treating subjects with a cervical carcinoma.