CaSki Cervical Cancer Cells Research Articles

MicroRNA-217 acts as a tumor suppressor and correlates with the chemoresistance of cervical carcinoma to cisplatin.

BackgroundMicroRNA-217 (miR-217) has been demonstrated to participate in the tumorigenesis and progression of various types of cancers. Nevertheless, the role of miR-217 in cervical carcinoma still remains not fully elucidated. This current work sought to investigate the role of miR-217 in the growth, migration, and invasion of cervical carcinoma and detect the role of miR-217 in the chemosensitivity of cervical carcinoma cell to cisplatin.Materials and methodsThe levels of miR-217 in 65 pairs of cervical carcinoma tissues and matched normal tissues were detected using quantitative real-time-PCR assay. The roles of miR-217 on the growth, apoptosis, migration, and invasion of cervical cancer SiHa and Ca-Ski cells were analyzed using Cell Counting Kit-8, flow cytometry, wound healing, and Transwell invasion assays, respectively. The target of miR-217 was identified using the online analysis tool TargetScan (http://www.targetscan.org/vert_72/) and was verified by luciferase reporter and immunoblotting assays. The xenograft tumor model was constructed to explore the impact of miR-217 on the growth of cervical carcinoma cell in vivo.ResultsThe level of miR-217 was remarkably lower in cervical carcinoma tissues than that in noncancerous tissues. Overregulation of miR-217 markedly suppressed the aggressiveness of cervical cancer cell and induced cell apoptosis through regulating V-Ki-Ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS). Finally, upregulation of miR-217 enhanced the chemosensitivity of both SiHa and Ca-Ski cervical cancer cells toward cisplatin.ConclusionAltogether, upregulation of miR-217 inhibits the aggressiveness phenotypes of cervical carcinoma cell via regulating KRAS gene and increases the sensitivity of cervical cancer cell to cisplatin.

Viral DNA integration and methylation of human papillomavirus type 16 in high-grade oral epithelial dysplasia and head and neck squamous cell carcinoma.

This study evaluated the integration and methlyation of human papillomavirus type 16 (HPV16) in head and neck squamous cell carcinoma (HNSCC) and its oral precursor, high-grade oral epithelial dysplasia (hgOED). Archival samples of HPV16-positive hgOED (N = 19) and HNSCC (N = 15) were evaluated, along with three HNSCC (UMSCC-1, -47 and -104) and two cervical cancer (SiHa and CaSki) cell lines. HgOED cases were stratified into three groups with increasing degrees of cytologic changes (mitosis, karyorrhexis and apoptosis). The viral load was higher and the E2/E6 ratio lower (indicating a greater tendency toward viral integration) in group 3 than in groups 1 or 2 (p = 0.002, 0.03). Methylation was not observed in hgOED cases and occurred variably in only three HNSCC cases (26.67%, 60.0% and 93.3%). In HNSCC cell lines, lower E7 expression correlated with higher levels of methylation. HgOED with increased cytologic change, now termed HPV-associated oral epithelial dysplasia (HPV-OED), exhibited an increased viral load and a tendency toward DNA integration, suggesting a potentially increased risk for malignant transformation. More detailed characterization and clinical follow-up of HPV-OED patients is needed to determine whether HPV-OED is a true precursor to HPV-associated HNSCC and to clarify the involvement of HPV in HNSCC carcinogenesis.

SiRNA interfering STAT3 enhances DDP sensitivity in cervical cancer cells.

Signal transducer and activator of transcription 3 (STAT3) is an important regulatory protein in the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway, which regulates cell proliferation, apoptosis, and other biological processes. It is closely related to tumor occurrence, progress, and resistance. Cisplatin (DDP) resistant cervical cancer cell line was established by shock induction to investigate the role of STAT3 in cervical cancer cells drug resistance. The expression of STAT3 in different chemotherapy response cervical cancer tissues was compared. The cervical cancer was divided into two groups upon STAT3 median level. Cervical cancer cell inhibitory rate by DDP treatment was compared. Western blot was used to detect STAT3 and phosphorylated STAT3 (p-STAT3) expressions in CaSki and CaSki/DDP cells. Cell apoptosis rate was tested by flow cytometry. CaSki/DDP cells were divided into small interfere RNA-normal control (siRNA-NC) group and siRNA-STAT3 group. Cell proliferation was evaluated by EdU staining. The rate of STAT3 over-expression in cervical cancer patients with no significant chemotherapy response was markedly higher than that with a significant response. The inhibitory effect of DDP on tumor cells derived from patients with low STAT3 expression was significantly higher, while the apoptosis rate was apparently lower than that of CaSki/DDP cells from patients with high STAT3 expression. siRNA-STAT3 transfection significantly reduced the expressions of STAT3 and p-STAT3, decreased cell proliferation, and enhanced cell apoptosis in CaSki/DDP cells. STAT3 over-expression is associated with DDP resistance in cervical cancer. Decreasing STAT3 can significantly promote the apoptosis of cervical cancer CaSki cells and decrease the DDP resistance.

Osthole enhances antitumor activity and irradiation sensitivity of cervical cancer cells by suppressing ATM/NF‑κB signaling.

Osthole (7-methoxy-8-isopentenoxycoumarin) is an O-methylated coumarin, originally extracted from Chinese herbal medicine. It has been demonstrated that osthole has antitumor effects in various cancer cells in vitro. The present study assessed the effects of osthole on the regulation of cervical cancer cell viability, apoptosis, and radiation sensitization. HeLa, SiHa, C-33A and CaSki cervical cancer cell lines were cultured and treated with osthole and/or irradiation and then subjected to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide cell viability, colony formation, apoptosis, acridine orange/ethidium bromide fluorescence staining, wound-healing, Transwell migration and invasion, immunofluorescence, Comet and western blot assays. The data showed that osthole dose-dependently reduced cervical cancer cell viability, proliferation, and migration and invasion, but induced apoptosis. At the protein level, osthole affected the expression of cervical cancer cell epithelial-mesenchymal transition markers, which showed that the expression of E-cadherin was increased, whereas that of vimentin was decreased. Osthole treatment also sensitized cervical cancer cells to irradiation, showing increased DNA damage as assessed by the Comet assay, and inhibited nuclear factor-κB signaling. In conclusion, osthole is an herbal agent that may offer potential for used as an adjuvant treatment for cervical cancer.

The combinational effect of E6/E7 siRNA and anti-miR-182 on apoptosis induction in HPV16-positive cervical cells

In the present research, we assumed that reducing the amounts of E6 and E7 oncoproteins by a specific siRNA sequence and recovering p53 and RB proteins, along with the recovery of the FOXO1 protein by applying anti-miR-182, would increase apoptosis and reduce proliferation rate in cancer cells. The HPV16-positive CaSki cervical cancer cell line was used. 48 hours after transfection of siRNA for targeting E6 and E7 oncoproteins and anti-miR-182, expression of its cellular targets p53, p21 and FOXO1 was assessed by real-time PCR, western blot analysis and immunocytofluorescence staining. In all treatments, apoptosis rate and viability were evaluated using Annexin-V-FITC apoptosis detection kits and MTT assays, respectively. Among the designed siRNAs, E6-1 and E7-2 proved the most effective in reducing E6 and E7 expressions by increasing the apoptotic rates to 12.4% and 16%, respectively, after 48 hours. Also, using anti-miR-182 increased apoptotic rate to 12.7% 48 hours after transfection of cervical cancer cells. The combinational use of either E6-1 or E7-2 siRNAs with anti-miR-182 resulted in a rise in apoptosis to 19.3% and 26%, respectively, higher than those obtained from the individual application of either without anti-miR-182. The simultaneous use of siRNA E6-1 and siRNA E7-2 with cisplatin increased sensitivity to cisplatin and reduced the viability of the cancer cells as compared to the use of cisplatin alone. The simultaneous use of cisplatin and anti-miR-182 had no considerable effect on viability or apoptosis rate compared to cisplatin alone.

Inhibition of Intracellular ROS Accumulation by Formononetin Attenuates Cisplatin-Mediated Apoptosis in LLC-PK1 Cells.

Cisplatin is a well-known anticancer drug frequently used for treating solid tumors, including ovarian, testicular, bladder, and cervical tumors. However, usage of cisplatin has been limited because of its adverse effects, particularly nephrotoxicity. Therefore, the present study sought to investigate the protective effect of formononetin against cisplatin-induced cytotoxicity in LLC-PK1 pig kidney epithelial cells as well as the anticancer effect of cisplatin in three different human cervical cancer cell lines, including HeLa, SiHa, and CaSKi cells. We first demonstrated that formononetin strongly prevented cisplatin-induced LLC-PK1 cell death. Although formononetin had no anticancer effect, it did not interrupt the anticancer effect of cisplatin in human cervical carcinoma cell lines. Furthermore, the treatment with formononetin reduced reactive oxygen species (ROS) accumulation and chromatin condensation. The percentage of Annexin V-positive cells also increased following cisplatin treatment. Finally, formononetin-inhibited c-Jun N-terminal kinase (JNK) phosphorylation, cleavage of caspase-8 and caspase-3, and the ratio of Bax to Bcl-2 increased with cisplatin. Taken together, these findings suggest that formononetin may be a possible option to prevent nephrotoxicity induced by cisplatin during treatment for cervical cancer.

Identification of (1S,4S)-2,5-diazabicyclo[2.2.1]heptane-dithiocarbamate-nitrostyrene hybrid as potent antiproliferative and apoptotic inducing agent against cervical cancer cell lines

The present study seeks to describe the design and synthesis of six new Michael adducts of (1S,4S)-2,5-diazabicyclo[2.2.1]heptane-dithiocarbamate with nitrostyrenes and their in vitro antiproliferative activity against human cervical cancer cell lines [HeLa (HPV 18 positive), CaSki (HPV 16 positive) and ViBo (HPV negative) cervical cancer cell lines]. Virtual screening of the physicochemical properties of all compounds have also been presented. All the compounds exploited significant antiproliferative activity on the three cervical cancer cell lines. Compound 8a was found to be most potent, displaying in vitro antiproliferative activity against HeLa, CaSki and ViBo cervical cancer cell lines superior to Cisplatin and Paclitaxel with IC50 values 0.99 ± 0.007, 2.36 ± 0.016 and 0.73 ± 0.002 μM respectively. In addition, compound 8a did not trigger the necrosis cell death to the test cancer cell lines. Further mechanistic study revealed that compound 8a could inhibit the cancer cell proliferation by inducing apoptosis through caspase-3 activation. Moreover, cell cycle analysis indicated that compound 8a could arrest the cell cycle at the G1 phase for HeLa and CaSki cancer cells. At the predetermined IC50 values on cancer cells, compound 8a did not induce any necrotic (cytotoxic) death to the normal human lymphocytes. In the present design, (1S,4S)-2,5-diazabicyclo[2.2.1]heptane system was found to be superior than the piperazine counterpart 11.

Increased high mobility group A 2 expression promotes transition of cervical intraepithelial neoplasm into cervical cancer.

Integration of the high risk human papillomavirus (HR-HPV) genome into host chromatin is an important step in cervical carcinogenesis. We identified HR-HPV integration sites within the human genome through detection of integrated papillomavirus sequences-PCR and assessed the role of high mobility group A 2 (HMGA2) in cervical carcinogenesis in clinical samples and cell lines. HPV integration sites were analyzed in 40 cervical cancer samples, while copy number variation and protein expression were assessed in 19 normal cervixes, 49 cervical intraepithelial neoplasia (CIN), and 52 cervical cancer samples. Overall, 25 HR-HPV integrating loci were detected in 24 cervical samples; HMGA2 was the only recurring integration site. Both HPV copy number and HMGA2 protein expression were higher in cervical cancer than CIN samples. Area under the curve (AUC) values for HMGA2 expression and HPV copy number were 0.910 (95% CI: 0.844–0.976) and 0.848 (95% CI: 0.772–0.923), respectively. Expression of Bcl-2 and Caspase 3 can indicate the cell proliferation and apoptosis. Transfection of HMGA2 siRNA decreased HMGA2 mRNA and protein expression, Bcl-2 expression, inhibited cell proliferation, and increased Caspase 3 expression and apoptosis in SiHa, CaSki and S12 cervical cancer cells. HMGA2 overexpression had the opposite effects. These results suggest that elevated HMGA2 expression is associated with transformation of CIN into cervical cancer and that HMGA2 might be a useful biomarker for assessing the risk of cervical lesion progression.

Identification of commonly regulated genes in HPV18- and HPV16-infected cervical cancer cells treated with the curcumin analogue 1,5-bis(2-hydroxyphenyl)-1,4-pentadiene-3-one

Objective: To identify commonly regulated genes in HPV-infected HeLa and CaSki cervical cancer cells treated with curcumin analogue 1,5-bis(2-hydroxyphenyl)-1,4-pentadiene-3-one (MS17) and to explore potential mechanisms that underlie its cytotoxic, anti-proliferative and apoptotic activity. Methods: HeLa and CaSki cells were treated with 2 × EC50 and 3 × EC50 doses of MS17 for 24 h and the RNA extracts were subjected to one-colour microarray-based gene expression profiling. Pair-wise significant genes (false discovery rate-corrected, P

Identification of Differentially Expressed Genes in CaSki Cervical Cancer Cells Treated with a Selected Diarylpentanoid

Identification of Differentially Expressed Genes in CaSki Cervical Cancer Cells Treated with a Selected Diarylpentanoid

MicroRNA-124-3p inhibits cell growth and metastasis in cervical cancer by targeting IGF2BP1.

MicroRNAs (miRs) serve a role in promoting and suppressing tumors in various types of malignant cancer, such as cervical cancer. However, the regulatory mechanism of miR-124-3p in cervical cancer remains unclear. In the present study, miR-124-3p was significantly downregulated in cervical cancer tissues and cell lines compared with matching adjacent non-tumor tissues and the normal cervical epithelial cell line End1/E6E7, respectively. Decreased expression of miR-124-3p was associated with advanced cervical cancer and the results of an in vitro study demonstrated that the ectopic expression of miR-124-3p significantly decreased the proliferation, migration and invasion of cervical cancer Caski cells. Furthermore, insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) was identified as a novel target of miR-124-3p. Overexpression of miR-124-3p decreased the expression of IGF2BP1, whereas miR-124-3p knockdown promoted IGF2BP1 expression at the post-transcriptional level in Caski cells. Additionally, overexpression of IGF2BP1 attenuated the suppressive effects of miR-124-3p on the proliferation, migration and invasion of Caski cells. IGF2BP1 was upregulated in cervical cancer tissues and cell lines compared with matching adjacent non-tumor tissues and the End1/E6E7 cell line, respectively. Therefore, the present study suggests that miR-124-3p suppresses the growth and metastasis of cervical cancer by directly targeting IGF2BP. Thus, miR-124-3p may be developed as a novel method of treating cervical cancer.

The receptor for activated protein kinase C promotes cell growth, invasion and migration in cervical cancer.

Cervical cancer is one of the most common malignant tumors in women all over the world. However, the exact etiology of cervical cancer remains unclear. The receptor for activated protein kinase C (RACK1) is reported to be involved in tumorigenesis and tumor progression. Besides, the prognostic value of RACK1 in several kinds of tumors has been identified. However, there are limited studies on the functional role of RACK1 in cervical cancer. In this study, we tested the expression level of RACK1 by immunohistochemistry and western blot technologies and find that it is upregulated in cervical cancer. Colony formation and CCK8 assays indicate that RACK1 promotes cell proliferation in CaSki cervical cancer cells. While the silence of RACK1 decreases the cell proliferation in CCK8 analysis. β-galactosidase staining suggests that RACK1 decreases cell senescence in cervical cancer cells. Invasion and migration assay show that RACK1 promotes the invasion and migration of cervical cancer cells. Also, when RACK1 was silenced, it exerts the opposite result. Furthermore, the mRNA expression levels of MMP-3, MMP-9 and MMP-10 were upregulated in RACK1-overexpressed CaSki cells by qPCR analysis. RACK1 also induces S phase accumulation in cell cycle analysis and suppresses cell apoptosis in cervical cancer cells. Flow cytometry analysis of mitochondria functions suggests that RACK1 increases the mitochondrial membrane potential (Δψm) levels to prevent mitochondrial apoptosis in cervical cancer cells. To explore the possible mechanism of RACK1, we tested and found that RACK1 upregulates the expression of NF-κB, cyclin D1 and CDK4 and downregulates the expression of p53, p38, p21 and STAT1 in cervical cancer cells. These results suggest that RACK1 promotes cell growth and invasion and inhibits the senescence and apoptosis in cervical cancer cells probably by affecting the p53 pathway.

Activation of the Wnt/β-catenin signaling pathway may contribute to cervical cancer pathogenesis via upregulation of Twist.

The Wnt signaling pathway regulates a number of biological processes. In the present study, the association between the Wnt signaling pathway and the pathogenesis of cervical cancer was investigated in the human cervical cancer CaSki cell line. An MTT assay was used to screen various concentrations of lithium chloride for use in subsequent experiments. Following incubation of CaSki cells with 0.05 and 0.1 mol/l lithium chloride, Twist and β-catenin were markedly upregulated at the mRNA and protein levels, respectively, compared with the untreated group, as measured by reverse transcription-polymerase chain reaction and western blotting. The results of the present study indicate that Wnt activation (which was induced by lithium chloride) and the subsequent upregulation of Twist may represent one of the molecular mechanisms underlying the occurrence and development of cervical cancer.

Novel prosurvival function of Yip1A in human cervical cancer cells: constitutive activation of the IRE1 and PERK pathways of the unfolded protein response

Cancer cells are under chronic endoplasmic reticulum (ER) stress due to hypoxia, low levels of nutrients, and a high metabolic demand for proliferation. To survive, they constitutively activate the unfolded protein response (UPR). The inositol-requiring protein 1 (IRE1) and protein kinase RNA-like ER kinase (PERK) signaling branches of the UPR have been shown to have cytoprotective roles in cancer cells. UPR-induced autophagy is another prosurvival strategy of cancer cells, possibly to remove misfolded proteins and supply nutrients. However, the mechanisms by which cancer cells exploit the UPR and autophagy machinery to promote survival and the molecules that are essential for these processes remain to be elucidated. Recently, a multipass membrane protein, Yip1A, was shown to function in the activation of IRE1 and in UPR-induced autophagy. In the present study, we explored the possible role of Yip1A in activation of the UPR by cancer cells for their survival, and found that depletion of Yip1A by RNA interference (RNAi) induced apoptotic cell death in HeLa and CaSki cervical cancer cells. Intriguingly, Yip1A was found to activate the IRE1 and PERK pathways of the UPR constitutively in HeLa and CaSki cells. Yip1A mediated the phosphorylation of IRE1 and also engaged in the transcription of PERK. The activation of these signaling pathways upregulated the expression of anti-apoptotic proteins and autophagy-related proteins. These events might enhance resistance to apoptosis and promote cytoprotective autophagy in HeLa and CaSki cells. The present study is the first to uncover a key prosurvival modulator, Yip1A, which coordinates IRE1 signaling with PERK signaling to support the survival of HeLa and CaSki cervical cancer cells.

Increased expression of PD‑L1 by the human papillomavirus 16 E7 oncoprotein inhibits anticancer immunity.

Cytotoxic T lymphocyte dysfunction is frequently associated with PD-L1/PD-1 pathway activation, and is a principal obstacle in cancer therapy. In the present study, the mechanisms underlying the human papillomavirus (HPV)-induced evasion of cervical cancer cells to the host immune system via the programmed death ligand 1/programmed death 1 (PD-L1/PD-1) signaling pathway was investigated. A significant increase in the expression of the HPV16E7 viral protein and PD-L1 in cervical tissues was observed when compared with normal cervical tissues. In addition, a positive correlation between HPV16E7 and PD-L1 expression was observed by immunohistochemical staining and reverse transcription-polymerase chain reaction. Overexpressing HPV16E7 oncoprotein in the epithelial carcinoma of PC3 cells increased the expression level of the PD-L1 protein and inhibited peripheral blood mononuclear cell (PBMC) proliferation and cytotoxic T lymphocyte (CTL) activity. Upon knockdown of HPV16E7 in HPV16-associated CaSki cervical cancer cells with a relevant siRNA, a reduction in PD-L1 protein expression was observed, as well as a significant increase in PBMC proliferation and CTL activity. A recombinant plasmid, MSCVPIG-soluble PD-1, was constructed and transfected into the CaSki cell line, and was co-cultured with PBMCs. PBMC proliferation and CTL activity were observed to increase significantly. In conclusion, the results presented in the current study suggest that overexpression of PD-L1, induced by HPV16E7, may be responsible for lymphocyte dysfunction. In addition, soluble PD-1 may restore the function of tumor-infiltrating lymphocytes by inhibiting the PD-L1/PD-1 signaling pathway. These results may provide a novel insight for immunotherapeutic approaches in the treatment of cervical cancer.

Characterization and Identification of Cryptic Biopeptides in Carya illinoinensis (Wangenh K. Koch) Storage Proteins.

The objective of this research was to identify and characterize the encoded peptides present in nut storage proteins of Carya illinoinensis. It was found, through in silico prediction, proteomic analysis, and MS spectrometry, that bioactive peptides were mainly found in albumin and glutelin fractions. Glutelin was the major fraction with ~53% of the nut storage proteins containing at least 21 peptides with different putative biological activities, including antihypertensives, antioxidants, immunomodulators, protease inhibitors, and inhibitors of cell cycle progression in cancer cells. Data showed that using 50 μg/mL tryptic digests of enriched peptides obtained from nut glutelins is able to induce up to 19% of apoptosis in both HeLa and CasKi cervical cancer cells. To our knowledge, this is the first report that shows the potential value of the nut-encoded peptides to be considered as adjuvants in cancer therapies.

Increased expression of PD-L1 by the human papillomavirus 16 E7 oncoprotein inhibits anticancer immunity.

Cytotoxic T lymphocyte dysfunction is frequently associated with PD‑L1/PD‑1 pathway activation, and is a principal obstacle in cancer therapy. In the present study, the mechanisms underlying the human papillomavirus (HPV)‑induced evasion of cervical cancer cells to the host immune system via the programmed death ligand 1/programmed death1 (PD‑L1/PD‑1) signaling pathway was investigated. A significant increase in the expression of the HPV16E7 viral protein and PD‑L1 in cervical tissues was observed when compared with normal cervical tissues. In addition, a positive correlation between HPV16E7 and PD‑L1 expression was observed by immunohistochemical staining and reverse transcription‑polymerase chain reaction. Overexpressing HPV16E7 oncoprotein in the epithelial carcinoma of PC3 cells increased the expression level of the PD‑L1 protein and inhibited peripheral blood mononuclear cell (PBMC) proliferation and cytotoxic Tlymphocyte (CTL) activity. Upon knockdown of HPV16E7 in HPV16‑associated CaSki cervical cancer cells with a relevant siRNA, a reduction in PD‑L1 protein expression was observed, as well as a significant increase in PBMC proliferation and CTL activity. A recombinant plasmid, MSCVPIG‑soluble PD‑1, was constructed and transfected into the CaSki cell line, and was co‑cultured with PBMCs. PBMC proliferation and CTL activity were observed to increase significantly. In conclusion, the results presented in the current study suggest that overexpression of PD‑L1, induced by HPV16E7, may be responsible for lymphocyte dysfunction. In addition, soluble PD‑1 may restore the function of tumor‑infiltrating lymphocytes by inhibiting the PD‑L1/PD‑1 signaling pathway. These results may provide a novel insight for immunotherapeutic approaches in the treatment of cervical cancer.

Role of Annexin A2 in the EGF-induced epithelial-mesenchymal transition in human CaSki cells.

The epidermal growth factor receptor (EGF-R) signaling pathway is thought to have an important role in the development and progression of several carcinomas, as it is associated with cell proliferation, differentiation and migration. Activation of EGF-R signaling regulates epithelial-mesenchymal transition (EMT)-associated invasion and migration in normal and malignant epithelial cells. However, the specific mechanisms have not yet been fully elucidated. The present study utilized wound healing assays, western blotting, flow cytometry and MTT assays to demonstrate that Annexin A2 (ANXA2) is a key regulatory factor in EGF-induced EMT in CaSki cervical cancer cells. Moreover, the increased expression levels of ANXA2 promoted cell viability and migration in human CaSki cells. It was also found that silencing ANXA2 partially reverses EGF-induced EMT and inhibits cell viability and migration in CaSki cells. These findings suggest that ANXA2 is a key regulator of EGF-induced EMT in CaSki cervical cancer cells.

STAT3 activity regulates sensitivity to tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis in cervical cancer cells.

In cervical cancer, p53-induced apoptosis is abrogated by human papilloma virus (HPV)-derived oncoproteinE6. Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) provides tumor-specific apoptosis in various cancers, including cervical cancer, the sensitivity differs depending on the cell lines. Signal transducer and activator of transcription 3 (STAT3) is a hub molecule that shifts the cellular fate to apoptosis or survival in response to cellular stresses. However, the contribution of STAT3 activity to TRAIL-induced apoptosis in cervical cancer remains unknown. We examined the TRAIL sensitivity in cervical cancer cells, using TRAIL-resistant (SiHa) and -sensitive (CaSki) cervical cancer cell lines and focused on STAT3 function involving the apoptotic pathway. STAT3 was inactivated by TRAIL stimulation in the CaSki cell line, but not in the SiHa cell line. We then inhibited STAT3 expression in the SiHa cell line using siRNA against STAT3 and suppressed STAT3 activity using a STAT3 inhibitor; both these treatments sensitized TRAIL-induced apoptosis in the SiHa cell line. Furthermore, the SiHa cells were exposed to tunicamycin (TM), an endoplasmic reticulum (ER) stress inducer that inactivates STAT3, with or without TRAIL. Accompanied by STAT3 inactivation, TM pretreatment significantly enhanced TRAIL-induced apoptosis. We therefore concluded that TRAIL-induced apoptosis was regulated by STAT3 in response to TRAIL stimulation. Our results also suggest that STAT3 inhibition increases the sensitivity of malignancies, particularly HPV-related cancer, to TRAIL-based therapy.

Synthesis of berberine-piperazine conjugates as potential antioxidant and cytotoxic agents

Piperazine derivatives bearing different electron-withdrawing and electron-donating functional groups were linked to the well-known isoquinoline alkaloid derivative, berberine via efficient organic transformations. The entire target berberine-based analogues were examined for their in vitro antioxidant potency using 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid bioassays, and anticancer activities using sulforhodamine B assay against HeLa and CaSki cervical cancer cell lines in addition to the cytotoxicity using Madin-Darby canine kidney non-cancer cell lines and, ascorbic acid and berberine used as a control for antioxidant and anticancer activities, respectively. Bioassay results revealed that newer compounds were more active against CaSki and HeLa cell lines with therapeutic indices better than that of parent berberine and showed tolerable cytotoxicity to the normal cells. A final analogue 5a with 4-methylpiperazine substituent indicated most significant anticancer potency with a therapeutic index of 58.53 (HeLa) and 48.76 (CaSki), followed by those bearing meta-chloropiperazine rings with a therapeutic index of 41.83 (HeLa) and 47.35 (CaSki), respectively.In addition, newly synthesized analogues exerted a significant radical scavenging activity against 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid cation with IC50 values of 8.917 µg/mL, and were good to moderate scavengers of 2,2-diphenyl-1-picrylhydrazyl radical with IC50 values of 25.40 µg/mL. Synthesized compound was characterized using several techniques, fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, 13C nuclear magnetic resonance, mass spectroscopy and elemental (CHN) analyses.