Cervical Cancer-derived Cell Lines Research Articles

A triple-drug combination induces apoptosis in cervical cancer-derived cell lines.

Cervical cancer is a worldwide health problem due to the number of deaths caused by this neoplasm. In particular, in 2020, 30,000 deaths of this type of tumor were reported in Latin America. Treatments used to manage patients diagnosed in the early stages have excellent results as measured by different clinical outcomes. Existing first-line treatments are not enough to avoid cancer recurrence, progression, or metastasis in locally advanced and advanced stages. Therefore, there is a need to continue with the proposal of new therapies. Drug repositioning is a strategy to explore known medicines as treatments for other diseases. In this scenario, drugs used in other pathologies that have antitumor activity, such as metformin and sodium oxamate, are analyzed. In this research, we combined the drugs metformin and sodium oxamate with doxorubicin (named triple therapy or TT) based on their mechanism of action and previous investigation of our group against three CC cell lines. Through flow cytometry, Western blot, and protein microarray experiments, we found TT-induced apoptosis on HeLa, CaSki, and SiHa through the caspase 3 intrinsic pathway, including the critical proapoptotic proteins BAD, BAX, cytochrome-C, and p21. In addition, mTOR and S6K phosphorylated proteins were inhibited in the three cell lines. Also, we show an anti-migratory activity of the TT, suggesting other targets of the drug combination in the late CC stages. These results, together with our former studies, conclude that TT inhibits the mTOR pathway leading to cell death by apoptosis. Our work provides new evidence of TT against cervical cancer as a promising antineoplastic therapy.

ATM Pathway Is Essential for HPV-Positive Human Cervical Cancer-Derived Cell Lines Viability and Proliferation.

Infection with some mucosal human papillomavirus (HPV) types is the etiological cause of cervical cancer and of a significant fraction of vaginal, vulvar, anal, penile, and head and neck carcinomas. DNA repair machinery is essential for both HPV replication and tumor cells survival suggesting that cellular DNA repair machinery may play a dual role in HPV biology and pathogenesis. Here, we silenced genes involved in DNA Repair pathways to identify genes that are essential for the survival of HPV-transformed cells. We identified that inhibition of the ATM/CHK2/BRCA1 axis selectively affects the proliferation of cervical cancer-derived cell lines, without altering normal primary human keratinocytes (PHK) growth. Silencing or chemical inhibition of ATM/CHK2 reduced the clonogenic and proliferative capacity of cervical cancer-derived cells. Using PHK transduced with HPV16 oncogenes we observed that the effect of ATM/CHK2 silencing depends on the expression of the oncogene E6 and on its ability to induce p53 degradation. Our results show that inhibition of components of the ATM/CHK2 signaling axis reduces p53-deficient cells proliferation potential, suggesting the existence of a synthetic lethal association between CHK2 and p53. Altogether, we present evidence that synthetic lethality using ATM/CHK2 inhibitors can be exploited to treat cervical cancer and other HPV-associated tumors.

Proteomics Analysis of Andrographolide-Induced Apoptosis via the Regulation of Tumor Suppressor p53 Proteolysis in Cervical Cancer-Derived Human Papillomavirus 16-Positive Cell Lines.

Regardless of the prophylactic vaccine accessibility, persistent infections of high-risk human papillomaviruses (hr-HPVs), recognized as an etiology of cervical cancers, continues to represent a major health problem for the world population. An overexpression of viral early protein 6 (E6) is linked to carcinogenesis. E6 induces anti-apoptosis by degrading tumor suppressor proteins p53 (p53) via E6-E6-associated protein (E6AP)-mediated polyubiquitination. Thus, the restoration of apoptosis by interfering with the E6 function has been proposed as a selective medicinal strategy. This study aimed to determine the activities of andrographolide (Androg) on the disturbance of E6-mediated p53 degradation in cervical cancer cell lines using a proteomic approach. These results demonstrated that Androg could restore the intracellular p53 level, leading to apoptosis-induced cell death in HPV16-positive cervical cancer cell lines, SiHa and CaSki. Mechanistically, the anti-tumor activity of Androg essentially relied on the reduction in host cell proteins, which are associated with ubiquitin-mediated proteolysis pathways, particularly HERC4 and SMURF2. They are gradually suppressed in Androg-treated HPV16-positive cervical cancer cells. Collectively, the restoration of p53 in HPV16-positive cervical cancer cells might be achieved by disruption of E3 ubiquitin ligase activity by Androg, which could be an alternative treatment for HPV-associated epithelial lesions.

Low RECK Expression Is Part of the Cervical Carcinogenesis Mechanisms.

Simple SummaryCervical cancer is one of the most lethal types of cancer in women from developing countries. These tumors are caused by long term infection with some human papillomavirus (HPV) types. Commonly, cervical cancer precursor lesions express high levels of matrix metalloproteinases. These enzymes break down specific components of the extracellular matrix affecting tissue structure and stiffness and cell motility. Matrix metalloproteinases and their natural inhibitors, such as Reversion-inducing Cysteine-rich protein with Kazal motifs (RECK) protein, are important in normal tissue maintenance and remodeling and play a major role in the transformation process. Here, we showed that RECK over expression reduced the tumorigenic capacity of cervical cancer cells in vivo. In addition, tumors over expressing RECK presented altered inflammatory infiltrating cells when compared to controls. Our findings are useful to further understand the biology of cervical cancer and can help to determine if RECK may be a good therapeutic target for cervical cancer treatment in the future.Human papillomavirus (HPV)-induced carcinogenesis comprises alterations in the expression and activity of matrix metalloproteinases (MMP) and their regulators. Reversion-inducing Cysteine-rich protein with Kazal motifs (RECK) inhibits the activation of specific metalloproteinases and its expression is frequently lost in human cancers. Here we analyzed the role of RECK in cervical carcinogenesis. Cervical cancer derived cell lines over expressing RECK were used to determine tumor kinetics as well as, cellular, immune and molecular properties in vivo. Besides, we analyzed RECK expression in cervical cancer samples. RECK over expression (RECK+) delayed tumor growth and increased overall survival in vivo. RECK+ tumors displayed an increase in lymphoid-like inflammatory infiltrating cells, reduced number and viability of tumor and endothelial cells and lower collagenase activity. RECK+ tumors exhibited an enrichment of cell adhesion processes both in the mouse model and cervical cancer clinical samples. Finally, we found that lower RECK mRNA levels were associated with cervical lesions progression and worse response to chemotherapy in cervical cancer patients. Altogether, we show that increased RECK expression reduced the tumorigenic potential of HPV-transformed cells both in vitro and in vivo, and that RECK down regulation is a consistent and clinically relevant event in the natural history of cervical cancer.

B7-H6, an immunoligand for the natural killer cell activating receptor NKp30, reveals inhibitory effects on cell proliferation and migration, but not apoptosis, in cervical cancer derived-cell lines

BackgroundAlthough great progress has been made in treatment regimens, cervical cancer remains as one of the most common cancer in women worldwide. Studies focusing on molecules that regulate carcinogenesis may provide potential therapeutic strategies for cervical cancer. B7-H6, an activating immunoligand expressed by several tumor cells, is known to activate NK cell-mediated cytotoxicity once engaged with its natural receptor NKp30. However, the opposite, that is, the effects in the tumor cell triggered by B7-H6 after interacting with NKp30 has not yet been well explored.MethodsIn this study, we evaluated the surface expression of B7-H6 by flow cytometry. Later, we stimulated B7-H6 positive cervical cancer derived-cell lines (HeLa and SiHa) with recombinant soluble NKp30 (sNKp30) protein and evaluated biological effects using the impedance RTCA system for cell proliferation, the scratch method for cell migration, and flow cytometry for apoptosis. Cellular localization of B7-H6 was determined using confocal microscopy.ResultsNotably, we observed that the addition of sNKp30 to the cervical cancer cell lines decreased tumor cell proliferation and migration rate, but had no effect on apoptosis. We also found that B7-H6 is selectively maintained in tumor cell lines, and that efforts to sort and purify B7-H6 negative or positive cells were futile, as negative cells, when cultured, regained the expression of B7-H6 and B7-H6 positive cells, when sorted and cultivated, lost a percentage of B7-H6 expression.ConclusionsOur results suggest that B7-H6 has an important, as of yet undescribed, role in the biology of the cervical tumor cells themselves, suggesting that this protein might be a promising target for anti-tumor therapy in the future.

Insulin growth factor-1 pathway in cervical carcinoma cancer stem cells.

Cancer stem cells (CSC) drive tumour progression and are implicated in relapse and resistance to conventional cancer therapies. Identification of differentially expressed genes by gene expression (GEP) profiling may help identify the differentially activated signalling pathways in cancer stem cells as opposed to bulk tumour cells which will provide new insights into cancer stem cell biology and aid in identification of novel therapeutic targets. Our study focused on the inhibition of CSC from cervical cancer cell lines by targeting insulin-like growth factor (IGF), which was identified by differential GEP. Targeted inhibition of IGF-1 by JB-1 trifluoroacetate (inhibitor of IGF) was carried out in SiHa, RSBS-14 and RSBS-43 cervical cancer derived cell lines. Effect of cisplatin was also evaluated. Inhibition of IGF-1 signalling was confirmed by demonstration of reduction in p-Akt levels. The cell biological effects of IGF-1 inhibition included an increase in G2M/S fraction, increased apoptosis and decreased invasive ability. JB-1 and cisplatin showed synergism. However, transcript levels of stemness and EMT markers showed variable levels following IGF inhibition. Overall, this proof-of-concept study has shown that IGF-1 is an attractive target for inhibition of CSC in invasive cervical cancer.

Selective photodynamic effects on cervical cancer cells provided by P123 Pluronic®-based nanoparticles modulating hypericin delivery

At present, cervical cancer is the fourth leading cause of cancer among women worldwide with no effective treatment options. In this study we aimed to evaluate the efficacy of hypericin (HYP) encapsulated on Pluronic® P123 (HYP/P123) photodynamic therapy (PDT) in a comprehensive panel of human cervical cancer-derived cell lines, including HeLa (HPV 18-positive), SiHa (HPV 16-positive), CaSki (HPV 16 and 18-positive), and C33A (HPV-negative), compared to a nontumorigenic human epithelial cell line (HaCaT). Were investigated: (i) cell cytotoxicity and phototoxicity, cellular uptake and subcellular distribution; (ii) cell death pathway and cellular oxidative stress; (iii) migration and invasion. Our results showed that HYP/P123 micelles had effective and selective time- and dose-dependent phototoxic effects on cervical cancer cells but not in HaCaT. Moreover, HYP/P123 micelles accumulated in endoplasmic reticulum, mitochondria and lysosomes, resulting in photodynamic cell death mainly by necrosis. HYP/P123 induced cellular oxidative stress mainly via type II mechanism of PDT and inhibited cancer cell migration and invasion mainly via MMP-2 inhibition. Taken together, our results indicate a potentially useful role of HYP/P123 micelles as a platform for HYP delivery to more specifically and effectively treat cervical cancers through PDT, suggesting they are worthy for in vivo preclinical evaluations.

E6/E7 and E6* From HPV16 and HPV18 Upregulate IL-6 Expression Independently of p53 in Keratinocytes.

Keratinocyte infection with high-risk human papillomavirus genotypes has been linked to cancer development. In cervix, the alpha HPV16 and HPV18 have been reported as the mayor causative agents of cervical cancer. Oncogenic progression and chronic inflammation are closely related processes, with IL-6 as one of the main pro-inflammatory cytokines involved. However, there are limited studies about the regulation of IL-6 by low and high risk HPVs and the HPV proteins implicated in this modulation. In this work, we report the overexpression of IL-6 in HPV infected cervical cancer derived cell lines (HeLa and SiHa) compared to non-tumorigenic keratinocytes (HaCaT), and in Cervical Intraepithelial Neoplasia grade 1 HPV16 and HPV18 positive cervical samples compared to HPV negative samples without lesions. Moreover, we generated HaCaT keratinocytes that express E5, E6, and E7 from high risk (16 or 18) or low risk (62 and 84) HPVs. E5 proteins do not modify IL-6 expression, while E7 modestly increase it. Interestingly, E6 proteins in HaCaT cells upregulate IL-6 mRNA expression and protein secretion. Indeed, in HaCaT cells that express high risk HPV16E6 or HPV18E6 proteins, only the truncated E6* isoforms were expressed, showing the stronger IL-6 overexpression, while in HaCaT cells that express low risk HPV62 and HPV84 full length E6 proteins, IL-6 was also upregulated but not so drastically. Since HaCaT cells have a mutated p53 form that is not degraded by the introduction of E6 or E6/E7, it seems that E6/E7 regulate IL-6 by an additional mechanism independent of p53. In addition, basal keratinocytes showed a strong expression of IL-6R using immunohistochemistry, suggesting an autocrine mechanism over proliferative cells. Altogether, IL-6 cytokine expression in keratinocytes is upregulated by E6 and E7 proteins from HPVs 16, 18, 62, and 84, especially by high risk HPV16 and HPV18 E6*, which may contribute to promote a pro-inflammatory and highly proliferative microenvironment that can persist over time and lead to cervical tumorigenesis.

Lactate secreted by cervical cancer cells modulates macrophage phenotype.

Cervical cancer continues to be a public health problem in developing countries. Previous studies have shown that cervical cancer cells display markers of aerobic glycolysis, indicating that these tumors are likely to secrete lactate. Mostly, lactate is recognized as a molecule capable of suppressing immune responses, through inhibition of T cells, Mϕs, and dendritic cells. We and others have previously shown that Mϕs are frequent cells infiltrating cervical cancers with the ability to inhibit antitumor immune responses and promote tumor growth through angiogenesis. Here, we have tested the hypothesis that lactate, secreted by cervical cancer cells, can modulate Mϕ phenotype. First, we showed higher lactate plasma concentrations in patients with increasing cervical lesion grades, with maximum concentration in the plasma of cancer patients, which supported our hypothesis. We then inhibited lactate production in tumor cell spheroids established from cervical cancer derived cell lines, using the lactate dehydrogenase inhibitor, oxamate, prior to co-culture with monocytes. Lactate mediated part of the crosstalk between tumor cells and Mϕs, promoting secretion of IL-1β, IL-10, IL-6, and up-regulation of hypoxia induced factor-1α expression, and down-regulation of p65-NFκB phosphorylation in Mϕs. We also showed that Mϕs from co-cultures treated with oxamate were better inducers of T cell activation. Of note, experiments performed with inhibition of the monocarboxylate transporters rendered similar results. Our data confirms the hypothesis that lactate, secreted by cervical tumor cells, influences the phenotype of tumor Mϕs, promoting a suppressive phenotype.

Artepillin C Induces Selective Oxidative Stress and Inhibits Migration and Invasion in a Comprehensive Panel of Human Cervical Cancer Cell Lines.

Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) is the main bioactive component of Brazilian green propolis, and possesses, among other things, anticancer properties. However, to the best of our knowledge, there are no studies of artepillin C in cervical cancer. To explore a new therapeutic candidate for cervical cancer, we have evaluated the effects of artepillin C on cellular viability in a comprehensive panel of human cervical cancer-derived cell lines including HeLa (human papillomavirus/HPV 18-positive), SiHa (HPV 16-positive), CaSki (HPV 16- and 18-positive) and C33A (HPV-negative) cells compared to a spontaneously immortalized human epithelial cell line (HaCaT). Our results demonstrated that artepillin C had a selective effect on cellular viability and could induce apoptosis possibly by intrinsic pathway, likely a result of oxidative stress, in all cancer-derived cell lines but not in HaCaT. Additionally, artepillin C was able to inhibit the migration and invasion of cancer cells. Thus, artepillin C appears to be a promising new candidate as an anticancer drug for cervical cancer induced by different HPV types.

Three Prime Repair Exonuclease 1 (TREX1) expression correlates with cervical cancer cells growth in vitro and disease progression in vivo

Alterations in specific DNA damage repair mechanisms in the presence of human papillomavirus (HPV) infection have been described in different experimental models. However, the global effect of HPV on the expression of genes involved in these pathways has not been analyzed in detail. In the present study, we compared the expression profile of 135 genes involved in DNA damage repair among primary human keratinocytes (PHK), HPV-positive (SiHa and HeLa) and HPV-negative (C33A) cervical cancer derived cell lines. We identified 9 genes which expression pattern distinguishes HPV-positive tumor cell lines from C33A. Moreover, we observed that Three Prime Repair Exonuclease 1 (TREX1) expression is upregulated exclusively in HPV-transformed cell lines and PHK expressing HPV16 E6 and E7 oncogenes. We demonstrated that TREX1 silencing greatly affects tumor cells clonogenic and anchorage independent growth potential. We showed that this effect is associated with p53 upregulation, accumulation of subG1 cells, and requires the expression of E7 from high-risk HPV types. Finally, we observed an increase in TREX1 levels in precancerous lesions, squamous carcinomas and adenocarcinomas clinical samples. Altogether, our results indicate that TREX1 upregulation is important for cervical tumor cells growth and may contribute with tumor establishment and progression.

Tobacco Exposure Enhances Human Papillomavirus 16 Oncogene Expression via EGFR/PI3K/Akt/c-Jun Signaling Pathway in Cervical Cancer Cells.

High-risk human papillomavirus (HR-HPV) infection is not a sufficient condition for cervical cancer development because most infections are benign and naturally cleared. Epidemiological studies revealed that tobacco smoking is a cofactor with HR-HPV for cervical cancer initiation and progression, even though the mechanism by which tobacco smoke cooperates with HR-HPV in this malignancy is poorly understood. As HR-HPV E6/E7 oncoproteins overexpressed in cervical carcinomas colocalize with cigarette smoke components (CSC), in this study we addressed the signaling pathways involved in a potential interaction between both carcinogenic agents. Cervical cancer-derived cell lines, CaSki (HPV16; 500 copies per cell) and SiHa (HPV16; 2 copies per cell), were acutely exposed to CSC at various non-toxic concentrations and we found that E6 and E7 levels were significantly increased in a dose-dependent manner. Using a reporter construct containing the luciferase gene under the control of the full HPV16 long control region (LCR), we also found that p97 promoter activity is dependent on CSC. Non-synonymous mutations in the LCR-resident TPA (12-O-tetradecanoylphorbol 13-acetate)-response elements (TRE) had significantly decreased p97 promoter activation. Phosphoproteomic arrays and specific inhibitors revealed that CSC-mediated E6/E7 overexpression is at least in part reliant on EGFR phosphorylation. In addition, we showed that the PI3K/Akt pathway is crucial for CSC-induced E6/E7 overexpression. Finally, we demonstrated that HPV16 E6/E7 overexpression is mediated by JUN. overexpression, c-Jun phosphorylation and recruitment of this transcription factor to TRE sites in the HPV16 LCR. We conclude that acute exposure to tobacco smoke activates the transcription of HPV16 E6 and E7 oncogenes through p97 promoter activation, which involves the EGFR/PI3K/Akt/C-Jun signaling pathway activation in cervical cancer cells.

Isolation of Biopsy-Derived, Human Cervical Keratinocytes Propagated as Monolayer and Organoid Cultures

The successful isolation and propagation of patient-derived keratinocytes from cervical lesions constitute a more appropriate model of cervical disease than traditional cervical cancer-derived cell lines such as SiHa and CaSki. Our aim was to streamline the growth of patient-obtained, cervical keratinocytes into a reproducible process. We performed an observational case series study with 60 women referred to colposcopy for a diagnostic biopsy. Main outcome measures were how many samples could be passaged at least once (n = 11), and where enough cells could be established, to precisely define their proliferation profile over time (n = 3). Altering cell culture conditions over those reported by other groups markedly improved outcomes. We were also successful in making freeze backs which could be resuscitated to successfully propagate multi-layered, organoids from cervical keratinocytes (n = 3). For best results, biopsy-intrinsic factors such as size and tissue digestion appear to be major variables. This seems to be the first systematic report with a well characterized and defined sample size, detailed protocol, and carefully assessed cell yield and performance. This research is particularly impactful for constituting a sample repository-on-demand for appropriate disease modelling and drug screening under the umbrella of personalized health.

Molecular iodine inhibits the expression of stemness markers on cancer stem-like cells of established cell lines derived from cervical cancer

BackgroundCancer stem cells (CSC) are characterized by deregulated self-renewal, tumorigenicity, metastatic potential, aberrant stemness signaling pathways, resistance to conventional therapy, and the ability to give rise to a progeny of proliferating cells that constitute the bulk of tumors. Targeting CSC will provide novel treatments for cancer. Different investigations have focused on developing complementary approaches that involve natural compounds that decrease chemo-resistance and reduce the side effects of conventional therapies. Since, it has been reported that molecular iodine (I2) exhibits antineoplastic effects and decreases tumor progression in some cancer models, we evaluated the potential effect of I2 on cell cultures enriched in cervical cancer stem-like cells.MethodsHeLa and SiHa cervical cancer cells were treated with 200uM I2 for 24 h. After time, cells were cultured in CSC-conditioned medium (cervospheres) and viability assays were performed. Following, tumorigenic capabilities in cervospheres treated with I2 were evaluated in NOD/SCID mice. HeLa monolayer cells untreated and their respective cervosphere cells treated or untreated with 200 μM of I2 for 24 h were xenotransplanted subcutaneously at different amounts and mice were monitored for at least 2 months.ResultsIn the present study, monolayer and CSC-enriched cultures (cervospheres) from cervical cancer-derived cell lines, HeLa and SiHa, showed that 200uM I2 supplementation inhibits proliferation of both and decreased their tumorigenic capacity, in vivo. This antineoplastic effect of I2 was accompanied by diminished expression of stemness markers including CD49f, CK17, OCT-4, NANOG, SOX2, and KLF4, as well as increased expression and activation of PPARγ receptors.ConclusionsAll this data led us to suggest a clinical potential use of I2 for targeting CSC and improve current treatments against cervical cancer.

Significance of CD133 positive cells in four novel HPV-16 positive cervical cancer-derived cell lines and biopsies of invasive cervical cancer

BackgroundCervical cancer is a major cause of cancer-related mortality in women in the developing world. Cancer Stem cells (CSC) have been implicated in treatment resistance and metastases development; hence understanding their significance is important.MethodsPrimary culture from tissue biopsies of invasive cervical cancer and serial passaging was performed for establishing cell lines. Variable Number Tandem Repeat (VNTR) assay was performed for comparison of cell lines with their parental tissue. Tumorsphere and Aldefluor assays enabled isolation of cancer stem cells (CSC); immunofluorescence and flow cytometry were performed for their surface phenotypic expression in cell lines and in 28 tissue samples. Quantitative real-time PCR for stemness and epithelial-mesenchymal transition (EMT) markers, MTT cytotoxicity assay, cell cycle analysis and cell kinetic studies were performed.ResultsFour low-passage novel cell lines designated RSBS-9, − 14 and − 23 from squamous cell carcinoma and RSBS-43 from adenocarcinoma of the uterine cervix were established. All were HPV16+. VNTR assay confirmed their uniqueness and derivation from respective parental tissue. CSC isolated from these cell lines showed CD133+ phenotype. In tissue samples of untreated invasive cervical cancer, CD133+ CSCs ranged from 1.3–23% of the total population which increased 2.8-fold in radiation-resistant cases. Comparison of CD133+ with CD133− bulk population cells revealed increased tumorsphere formation and upregulation of stemness and epithelial-mesenchymal transition (EMT) markers with no significant difference in cisplatin sensitivity.ConclusionLow-passage cell lines developed would serve as models for studying tumor biology. Cancer Stem Cells in cervical cancer display CD133+ phenotype and are increased in relapsed cases and hence should be targeted for achieving remission.

Platelet-Activating Factor Receptor Ligands Protect Tumor Cells from Radiation-Induced Cell Death.

Irradiation generates oxidized phospholipids that activate platelet-activating factor receptor (PAFR) associated with pro-tumorigenic effects. Here, we investigated the involvement of PAFR in tumor cell survival after irradiation. Cervical cancer samples presented higher levels of PAF-receptor gene (PTAFR) when compared with normal cervical tissue. In cervical cancer patients submitted to radiotherapy (RT), the expression of PTAFR was significantly increased. Cervical cancer-derived cell lines (C33, SiHa, and HeLa) and squamous carcinoma cell lines (SCC90 and SCC78) express higher levels of PAFR mRNA and protein than immortalized keratinocytes. Gamma radiation increased PAFR expression and induced PAFR ligands and prostaglandin E2 (PGE2) in these tumor cells. The blocking of PAFR with the antagonist CV3938 before irradiation inhibited PGE2 and increased tumor cells death. Similarly, human carcinoma cells transfected with PAFR (KBP) were more resistant to radiation compared to those lacking the receptor (KBM). PGE2 production by irradiated KBP cells was also inhibited by CV3988. These results show that irradiation of carcinoma cells generates PAFR ligands that protect tumor cells from death and suggests that the combination of RT with a PAFR antagonist could be a promising strategy for cancer treatment.

MicroRNA-200c suppressed cervical cancer cell metastasis and growth via targeting MAP4K4.

To dissect the functioning mode of miR-200c on cervical cancer cell metastasis and growth and provide therapeutic targets for cervical cancer. By quantitative Real-time polymerase chain reaction, the miR-200c expression level in 42 pairs of cervical cancer tissue samples and six cervical cancer-derived cell lines were examined. Using miR-200c mimics, we analyzed the effects of miR-200c over-expression on cell proliferation, invasion, and migration. Dual-luciferase activity assay was recruited to examine the potential target gene MAP4K4 that predicted by several databases. Protein level was studied using Western blot. miR-200c expressed significantly lower in cervical cancer tissue samples and cell lines. And over-expression of miR-200c in cervical cancer cells significantly decreased the cell invasion, migration and proliferation abilities. Dual-luciferase and Western blot confirmed MAP4K4 as a target gene of miR-200c. Furthermore, up-regulation of MAP4K4 counteracted the suppressive effect of miR-200c over-expression on cell growth and metastasis. miR-200c could suppress cervical cancer cell proliferation and progression via regulating MAP4K4, which might provide a new target for cervical cancer diagnosis and therapy.

Abstract B69: Study of superoxide dismutase-2 protein in HPV-mediated cell transformation

Abstract Oxidative stress reflects an imbalance in the maintenance of the intracellular redox state resulting in the accumulation of oxidant species that may contribute to tumorigenesis. The superoxide dismutase 2 protein (SOD2) contributes to cell homeostasis by catalyzing the dismutation of superoxide anion radicals in oxygen and hydrogen peroxide, preventing the direct inactivation of biomolecules. SOD2 protein can be induced by the activation of the NF-kB pathway in several cell types following treatment with interleukin 1β (IL-1β) and tumor necrosis factor alpha (TNFα), both proinflammatory cytokines. In addition, previous studies from the group have shown a direct correlation between increased levels of SOD2 protein and severity of uterine cervix lesions. The aim of this study is to elucidate the involvement of SOD2 in the pathogenesis associated with HPV and in the effect of proinflammatory cytokines. Methods: Primary human keratinocytes transduced with HPV16 oncogenes and cervical cancer derived cell lines were treated with the proinflammatory cytokines TNFα, and IL-1beta. The expression of SOD2 protein involved in IL-1 β and TNFα signaling pathways was determined by Western blot and ELISA. Results: Preliminary results suggest the presence of higher levels of SOD2 expression in uterine cervix-derived tumor cell lines when compared to normal primary keratinocytes. Treatment with IL-1β and TNFα induces SOD2 protein accumulation in in the HPV16 positive cervical-derived tumor line, SiHa. On the other hand, no SOD2 induction was observed in the HPV-negative cervical cancer derived cell line C33. Further replications and additional experiments are needed for conclusions. Citation Format: Gabriela Ávila Fernandes Silva, Rafaella Almeida Lima Nunes, Enrique Boccardo, Luisa Lina Villa, Lara Termini. Study of superoxide dismutase-2 protein in HPV-mediated cell transformation [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr B69.

Abstract 1100: Synergistic interaction between gemcitabine and PD-0325901 in C-33A cervical carcinoma cell line

Abstract Cervical cancer affects over half a million women worldwide, and is one of the most common causes of death in women. Treatment of cervical cancers consists of surgery, radiation, chemotherapy, or combination of therapies. However, about half of patients with advance cancer will show recurrent tumors. Signaling cascades are often dysregulated in human cancer cells making them attractive targets for combination drug therapies. PD-0325901, an inhibitor of the mitogen-activated protein kinase, is a promising target for metastatic cancer. Another drug used to treat cervical carcinoma is gemcitabine, a nucleoside analog inhibitor of the ribonucleotide reductase and DNA damage inducible protein 45a (Gadd45a). This drug is generally used in combination with other drugs, after reoccurrence of the disease state. We decided to evaluate the efficacy of gemcitabine in combination with PD-0325901 in C-33A, a metastatic cervical cancer-derived cell line. We evaluated the potency of gemcitabine and PD-0325901 alone and in combination. Cell viability after incubation with the drugs was determined at 72 hours and at 7 days by measuring ATP content. Synergy was determined assessed utilizing BIOENSIS’s suite of drug combination analysis tools including: isobologram, combination index (CI) and Bliss analysis. Isobologram analysis at 72 hours of incubation revealed that the mean values of the observed data were significantly smaller than those of the predicted maximum additive values, indicating synergy. Bliss and combination index analysis confirmed the observation, showing a synergistic effect at concentrations between 2 - 200 nM PD-0325901 and 0.3 - 3 nM gemcitabine. Similar patterns of synergy were observed with 7 day incubations of C-33A with gemcitabine and PD-0325901. These results indicate that gemcitabine and PD-0325901 showed significantly more growth inhibition than either drug alone in the C-33A tumor cell line, suggesting that the combination of gemcitabine - PD-0325901 could be used in cervical cancer therapy. Citation Format: Macarena Irigoyen, Gonzalo Castillo. Synergistic interaction between gemcitabine and PD-0325901 in C-33A cervical carcinoma cell line [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1100. doi:10.1158/1538-7445.AM2017-1100

EMMPRIN Inhibits bFGF-Induced IL-6 Secretion in an Osteoblastic Cell Line, MC3T3-E1.

Background: Electrolytically-generated acid functional water (FW) is obtained by electrolyzing low concentrations of saline. Although it has been widely used in clinical practice with various purposes, the underlying mechanisms of action involved have not been fully elucidated so far. We used the human cervical cancer-derived fibroblastic cell line (HeLa), to examine the cytokine secretion profile following FW treatment in the present study.Results: FW stimulation significantly induced the secretion of basic fibroblast growth factor (bFGF) and extracellular matrix metalloproteinase inducer (EMMPRIN). The effect of both factors on osteoblast-like MC3T3-E1 cells was further examined by stimulating the cells with the conditioned medium of FW-stimulated HeLa cells. However, the conditioned medium failed to induce IL-6 secretion. The MC3T3-E1 cells were further stimulated with recombinant bFGF or EMMPRIN or a combination of both factors. Intriguingly, bFGF-stimulated IL-6 induction was totally inhibited by EMMPRIN. Pretreatment with the specific inhibitor of nuclear factor-kappa B (NF-κB) drastically inhibited IL-6 secretion indicating that bFGF-induced IL-6 expression was dependent on NF-κB activation. The phosphorylation status of NF-κB p65 subunit was further examined. The results indicated that EMMPRIN inhibited bFGF-induced NF-κB p65 phosphorylation.Conclusions: These findings suggest that bFGF can induce IL-6 secretion in MC3T3-E1 cells through NF-κB activation. As EMMPRIN inhibited bFGF-induced IL-6 secretion by reducing the p65 subunit phosphorylation, it might be concluded that bFGF and EMMPRIN crosstalk in their respective signaling pathways.