Hsa_circ_0000119 promoted ovarian cancer development via enhancing the methylation of CDH13 by sponging miR-142-5p.

Ovarian cancer is the leading cause of gynecological cancer-related death in women, and is difficult to treat. The aim of our study is to explore the role and action mechanism of hsa_circ_0000119 in ovarian cancer, thus to analyze whether the circular RNA is a potential target for the treatment of the disease. In this present study, our data shows that hsa_circ_0000119 and DNA methyltransferase 1 (DNMT1) was increased, while miR-142-5p was decreased in ovarian cancer. Overexpression of hsa_circ_0000119 promoted tumor growth, while silencing of hsa_circ_0000119 resulted in an opposite effects. Decreasing of hsa_circ_0000119 also notably inhibited the proliferation, migration, and invasion of the ovarian cancer cells. Moreover, the data proves that hsa_circ_0000119 negatively regulated miR-142-5p and cadherin 13 (CDH13) expression, but positively regulated DNMT1 expression. miR-142-5p could interact with hsa_circ_0000119 and DNMT1 3'-UTR. Silencing of DNMT1 could reverse the inhibition of hsa_circ_0000119 to miR-142-5p and CDH13 expression. Importantly, higher level of CDH13 promoter methylation existed in the ovarian tumors than that in matched normal tissues. DNA methyltransferase inhibitor could increase the expression of CDH13 in ovarian cancer cells. In addition, our results also prove that increasing of CDH13 or miR-142-5p effectively reversed the inhibition of hsa _circ_0000119 to the cell malignant phenotypes. Overall, our data demonstrate that hsa_circ_0000119 facilitated ovarian cancer development through increasing CDH13 expression via promoting DNMT1 expression by sponging miR-142-5p. Our data demonstrate the potential role of hsa_circ_0000119 in the treatment of ovarian cancer.

CircRNA hsa_circ_0001627 aggravates cervical cancer progression through upregulation of FNDC3B and activating PI3K/mTOR signaling pathway.

Circular RNAs (CircRNAs) are key regulators in the development and progression of human cancers. However, the biological roles and mechanisms of circRNAs in gastric cancer (GC) remain largely unknown. Analyzing circRNA microarray dataset (GSE102686) and clinical specimens, a novel circRNA termed hsa_circ_0001627, was identified and it was highly expressed in CC cancerous tissues and cells, and was associated with poor clinical outcomes. Functionally, hsa_circ_0001627 silencing impaired the malignant progression of CC cells and the growth of CC xenografts in nude mice. Mechanistically, hsa_circ_0001627 acted as a miR-1225-5p sponge, thus indirectly regulating FNDC3B and leading to the activation of PI3K/mTOR signaling pathway. Collectively, the present study indicates that hsa_circ_0001627 regulates miR-1225-5p/FNDC3B/PI3K/mTOR axis and functions as an oncogene in CC progression, suggesting the potential therapeutic use of hsa_circ_0001627 in CC treatment.

CircWHSC1 expedites cervical cancer progression via miR-532-3p/LTBP2 axis.

Dysregulated circRNAs have potential roles in the progression of various cancer types, including cervical cancer (CaCx). The carcinogenic roles of circRNA Wolf-Hirschhorn syndrome candidate gene-1 (circWHSC1) are described in the development of diverse cancers. The objective of this study was to investigate the expression and the underlying role of circWHSC1 in CaCx. The expression of circWHSC1 was detected by real-time PCR. After the suppression of circWHSC1 expression, the changes in the proliferation, migration, invasion, and apoptosis capacities were detected by CCK-8 assay, colony formation assay, Transwell assays, flow cytometry, and the determination of apoptosis-related proteins. The interplay among circWHSC1, miR-532-3p, and latent transforming growth factor-ß binding protein 2 (LTBP2) was confirmed by luciferase reporter and biotinylated RNA pull-down assays. A nude mice xenograft tumor model was established to evaluate the anti-tumorigenic role of circWHSC1 silencing in vivo. CircWHSC1 was overexpressed in CaCx tissues and cell lines and its high expression was inversely associated with the survival rate of patients with CaCx. CircWHSC1 silencing was capable of suppressing the proliferation, metastasis, and invasion of tumor cells and inducing apoptosis. Investigation to its molecular mechanism revealed that circWHSC1 functioned as a competitive endogenous RNA (ceRNA), mediating LTBP2 expression by targeting miR-532-3p. The in vivo experiments further confirmed the inhibition of tumor growth and metastasis by circWHSC1 knockdown. The circWHSC1-mediated miR-532-3p/LTBP2 signaling axis might be a novel therapeutic target for CaCx.

Amino acid transporters: Emerging roles in drug delivery for tumor-targeting therapy.

Amino acid transporters, which play a vital role in transporting amino acids for the biosynthesis of mammalian cells, are highly expressed in types of tumors. Increasing studies have shown the feasibility of amino acid transporters as a component of tumor-targeting therapy. In this review, we focus on tumor-related amino acid transporters and their potential use in tumor-targeting therapy. Firstly, the expression characteristics of amino acid transporters in cancer and their relationship with tumor growth are reviewed. Secondly, the recognition requirements are discussed, focusing on the "acid-base" properties, conformational isomerism and structural analogues. Finally, recent developments in amino acid transporter-targeting drug delivery strategies are highlighted, including prodrugs and nanocarriers, with special attention to the latest findings of molecular mechanisms and targeting efficiency of transporter-mediated endocytosis. We aim to offer related clues that might lead to valuable tumor-targeting strategies by the utilization of amino acid transporters.

Oleandrin induces apoptosis via activating endoplasmic reticulum stress in breast cancer cells.

BACKGROUND: Breast cancer is the most common malignant tumor in women. Due to limited treatment outcome and high rate of metastasis, the prognosis is especially poor for triple-negative breast cancer. It is urgent to discover and develop novel agents for treatment of breast cancer. Herein, we investigated the potential mechanisms of Oleandrin's (a cardiac glycoside) cytotoxic activity against breast cancer cells. METHODS: Cell proliferation was assessed by xCELLigence Real-Time Cell Analyzer (RTCA)-MP system. Apoptotic cells were detected by using Annexin V/PI staining and nuclear fragments observation. The effect of oleandrin on ATP1B3 expression and markers of ER stress were determined by western blot. A primary cell sensitivity assay was performed via a collagen gel droplet-embedded culture drug sensitivity method (CD-DST). RESULTS: Oleandrin suppressed cell proliferation and colony formation in the three breast cancer cell lines but did not affect normal mammary epithelial cells. Additionally, the expression of ATP1B3 was higher in the three breast cancer cell lines compared to MCF10A cells. Treatment with oleandrin increased the number of apoptotic cells and led to nuclear pyknosis, fragmentation, and apoptotic body formation in breast cancer cells. Furthermore, oleandrin treatment increased expression of Bax and Bim but decreased that of Bcl-2. Treatment with oleandrin also upregulated the expression of endoplasmic reticulum stress associated proteins, including eIF2α, ATF4, and CHOP, but not PERK. oleandrin treatment also induced the phosphorylation of PERK and eIF2α. Of note, oleandrin exhibited antitumor effects on patient-derived breast cancer cells under three-dimensional culture conditions. CONCLUSIONS: Taken together, our results suggest that oleandrin induces mitochondrial-mediated apoptosis by activating endoplasmic reticulum stress in breast cancer. Moreover, oleandrin may be an effective strategy for the treatment of breast cancer.

MiR-144 suppresses proliferation, invasion, and migration of breast cancer cells through inhibiting CEP55.

OBJECTIVE: The study aimed to investigate the molecular mechanism of miR-144 and CEP55 as well as the influence of their interaction on the cell proliferation, migration, invasion, cell cycle and cell apoptosis in breast cancer. METHODS: In this study, The Cancer Genome Atlas (TCGA, https://tcga-data.nci.nih.gov/ ) database was used for microarray analysis. The expressions of miR-144 and CEP55 in 40 adjacent tissues and 36 tumor tissues were examined by western blot, qRT-PCR and immunohistochemistry. The target relationship between miR-144 and CEP55 was predicted and confirmed by TargetScan and luciferase reporter assay. The cell proliferation, cell cycle and cell apoptosis in different groups were detected by MTT and flow cytometry assays, while wound healing and transwell assays were used for the cell migration and invasion tests. The regulatory effects of miR-144 and CEP55 on breast tumor were verified through nude mouse model in vivo experiment. RESULTS: MiR-144 was down-regulated in breast cancerous tissues and cells, whereas CEP55 expression was up-regulated in breast cancerous tissues. Moreover, there existed a target relationship between miR-144 and CEP55 and negative correlation on their expressions. MiR-144 could down-regulate CEP55 expression, thereby inhibiting proliferation, invasion, migration, retarding cell cycle and accelerating cell apoptosis. MiR-144 could inhibit cell progression through down-regulating CEP55 in vivo. CONCLUSION: MiR-144 suppressed cell proliferation, migration, invasion and induced cell cycle arrest and cell apoptosis by repressing CEP55. This might provide a promising therapy for clinical treatment.

The omega-3 polyunsaturated fatty acid docosahexaenoic acid inhibits proliferation and progression of non-small cell lung cancer cells through the reactive oxygen species-mediated inactivation of the PI3K /Akt pathway.

BACKGROUND: Docosahexaenoic acid(DHA) inhibits tumor growth and progression in various cancers, including lung cancer. However, the mechanisms involved remain unclear. The aim of this study was to identify the mechanism of DHA in inhibiting progression of non-small cell lung cancer (NSCLC) in vitro. METHODS: The proliferation of A549 was tested by MTT, and cell apoptosis was analysed using flow cytometer. The migration and invasion were examined respectively by wound healing assay and Transwell invasion assay. The level of ROS (reactive oxygen species, ROS) was checked by DCF (dichlorodihydrofluorescein, DCF) production in cells. The apoptosis associated protein (caspase-3, PARP,Bax,Bcl-2 and survivin) and metastases associated proteins including HEF1, MMP9 and VEGF were detected by Western blot, and the same method was used in the expression of PI3K and Akt. RESULTS: DHA inhibited proliferation and induced apoptosis of A549 cells. Moreover, it suppressed the invasion and metastasis of A549 cells, while downregulating the levels of metastasis-associated proteins, including HEF1, matrix metallopeptidase (MMP9), and vascular endothelial growth factor (VEGF), in a dose -dependent manner. In addition, DHA inactivated Akt phosphorylation. All of these responses were associated with the accumulation of intracellular ROS. DHA downregulated the level of antioxidant enzymes such as catalase, while the antioxidant N-acetyl-cysteine (NAC) reversed the effect of DHA, which further validated our findings. CONCLUSIONS: The present study demonstrates that DHA inhibits the development of non-small lung tumors through an ROS-mediated inactivation of the PI3K/Akt signaling pathway.

Inhibition of MDM2 Re-Sensitizes Rapamycin Resistant Renal Cancer Cells via the Activation of p53.

BACKGROUND/AIMS: Rapamycin is a potential anti-cancer agent, which modulates the activity of mTOR, a key regulator of cell growth and proliferation. However, several types of cancer cells are resistant to the anti-proliferative effects of rapamycin. In this study, we report a MDM2/p53-mediated rapamycin resistance in human renal cancer cells. METHODS: Trypan blue exclusion tests were used to determine the cell viability. Changes in mRNA and protein expression were measured using real-time PCR and western blot, respectively. Xenograft models were established to evaluate the in vivo effects of rapamycin combined with a MDM2 inhibitor. RESULTS: Rapamycin treatment suppresses the expression of MDM2 and exogenous overexpression of MDM2 in A498 cells contributes to rapamycin resistance. By establishing a rapamycin resistant cell line, we observed that MDM2 was significantly upregulated in rapamycin resistant cells than that in rapamycin sensitive cells. Importantly, the rapamycin resistant cells demonstrated attenuated accumulation of p53 in the nucleus in response to rapamycin treatment. Moreover, the inhibition of MDM2 by siMDM2 sensitizes A498 cells to rapamycin through the activation of p53. In both in vitro and in vivo models, the combination of rapamycin with the MDM2 inhibitor, MI-319, demonstrated a synergistic inhibitory effect on rapamycin resistant cells. CONCLUSION: Our study reports a novel mechanism for rapamycin resistance in human renal cancer and provides a new perspective for the development of anti-cancer drugs.

Interference of lysine-specific demethylase 1 inhibits cellular invasion and proliferation in vivo in gastric cancer MKN-28 cells.

BACKGROUND: Lysine-specific demethylase 1(LSD1), the first identified histone demethylase, plays an important role in the epigenetic regulation of gene activation and repression. Up-regulated LSD1expression has been reported in several malignant tumors.Our aim, therefore, was to better understand the mechanisms underlying the upregulation of LSD1 in gastric cancer. METHODS: We used lentiviral shRNA to knockdown LSD1 in the gastric cancer MKN-28 cell line. Cell proliferation was measured by MTT assay while cell apoptosis was assessed by Annexin V-FITC/PI double staining flow cytometry. The invasive potential of gastric cancer cells was determined by matrigel invasion assay. Protein expression was detected by Western blot. In vivo, the effect of knocking down LSD1 on tumor growth and protein expression in gastric cancer cells in nude mice was investigated. RESULTS: LSD1 knockdown in MKN-28 cell lines resulted in increasing the activity of cisplatin in vitro and the inhibition of cancer cell proliferation and invasion, and induced cell apoptosis. The expression of TGF-ß1, VEGF, Bcl-2, ß-catenin, p-ERK and p-Smad 2/3 proteins was inhibited in LSD1 knockdown cells. Moreover, in an in vivo model of gastric cancer, LSD1 knockdown suppressed tumor growth and protein expression. CONCLUSION: LSD1 knockdown affected the fuction of gastric cancer MKN-28 cell line. LSD1 may be a latent target in the diagnosis and therapy of gastric cancer.

The vitamin D receptor gene ApaI polymorphism is associated with increased risk of renal cell carcinoma in Chinese population.

Molecular epidemiologic studies previously reported that 1,25-dihydroxy vitamin D3 (1,25(OH)2 D3) appears to influence cancer risk. It exerts its activity through the intracellular vitamin D receptor (VDR), which regulates the transcription of genes. This study aimed to investigate the genetic association of VDR polymorphisms with renal cell carcinoma (RCC) risk in the Chinese population. The genotypes of five VDR polymorphisms (TaqI, BsmI, Cdx-2, ApaI, and FokI) were studied using polymerase chain reaction in 302 RCC patients and 302 healthy controls. ApaI variant AA and AC genotypes were found to be associated with a significantly increased risk of RCC compared with the CC genotype (OR = 2.60, 95% CI = 1.39-4.85 for AA vs. CC, and OR = 1.52, 95% CI = 1.08-2.13 for AC vs. CC). The AA genotype was also associated with a higher Fuhrman grade (OR = 2.87, 95% CI = 1.15-7.16 for AA vs. CC). No significant difference was found between the other four VDR polymorphisms and RCC risk. Our study suggests that VDR ApaI genotypes may be involved in the increased risk and progression of RCC in the Chinese Han population.

Analysis of APC mutation in human ameloblastoma and clinical significance.

As a highly conserved signaling pathway, Wnt/ß-catenin signal transduction pathway plays an important role in many processes. Either in the occurrence or development of tumor, activation of this pathway takes an important place. APC inhibits Wnt/ß-catenin pathway to regulate cell proliferation and differentiation. This study aimed to investigate the function of cancer suppressor gene. PCR amplification and sequencing method was used to analyze APC mutations of human clinical specimens. The pathological specimens were collected for PCR and clear electrophoretic bands were obtained after electrophoresis. The gene sequence obtained after purification and sequencing analysis was compared with the known APC gene sequence (NM_000038.5). Base mutations at APC 1543 (T â†’ C), APC-4564 (G â†’ A), APC-5353 (T â†’ G), APC-5550 (T â†’ A) and APC-5969 (G â†’ A) locus existed in 22 (27.5 %), 12 (15 %), 5 (6.25 %), 13 (16.25 %) and 12 patients (15 %), respectively. Gene mutations existed in ameloblastoma, and the mutation loci were 1543 locus (T â†’ C), 4564 locus (G â†’ A), 5353 locus (T â†’ G), 5550 locus (T â†’ A) and 5969 locus (G â†’ A) 15 %, respectively. APC mutation plays a certain role in monitoring the tumor malignant degree as it may indicate the transition process of ameloblastoma malignant phenotype.

Antitumor effect of dendritic cells transfected with prostate-specific membrane antigen recombinant adenovirus on prostate cancer: An in vitro study.

The aim of the present study was to construct a dendritic cell (DC) vaccine transfected with a prostate-specific membrane antigen (PSMA) recombinant adenovirus and to observe the ability of the recombinant DCs in eliciting a PSMA-directed T­cell response to prostate cancer (PCa) in vitro. Replication­defective adenoviral vectors, were constructed using the Adxsi system. The virus titer was measured by TCID50 assay, and the expression of the PSMA gene was identified by polymerase chain reaction (PCR) generation of peripheral blood mononuclear cell (PBMC) derived DCs in vitro. In addition, a PE­7AAD apoptosis and necrosis kit was applied to detect the survival of DCs at different MOI values to determine the optimal MOI. Morphological changes of DC were observed under a fluorescence microscope, expression of the PSMA protein was detected by western blotting 48 h after transfection, the expression of DC markers prior to and following transfection was detected by direct immunofluorescence, and the interleukin (IL)-12 concentration in the culture supernatant of the three groups was measured by ELISA. The antitumor effect of DC-stimulated cytotoxic T lymphocytes (CTLs) on different PCa cell lines was analyzed using a Cell Counting Kit­8 assay. The optimal MOI value was determined to be 200. The PSMA protein was expressed in DCs, and the recombinant adenovirus did not impact the maturation and morphological changes of the DCs. The expression levels of the co-stimulatory molecules, CD80, CD83, CD86 and HLA­DR, were significantly higher in the Ad­PSMA­DC group than in the other two groups (P<0.05). The concentration of IL­12 in the supernatant of the Ad­PSMA­DC group (79.51±1.60 pg) was comparable with that of the Ad­GFP­DC group (not significantly different), and the two were significantly higher than the non­transfection group (P<0.05). The optimal effector to target (E:T) ratio was determined to be 40:1. However, at the same E:T ratio, the cytotoxic activity of PSMA­DC­T against the LNCap cells was markedly stronger than its activity against the other target cells (DU145 and 22RV; P<0.05); furthermore, the the cytotoxic activity of PSMA-DC-T against the LNCap cells was significantly higher than the anti­LNCap effect of DC­T cells in other groups (P<0.05). In vitro experiments indicated that mature DCs transfected with Ad­PSMA secreted high concentrations of IL­12 and elicited potent antitumor immune responses targeting PSMA­expressing cells by stimulating the cytotoxic activity of CTLs.

The variation trends of SFRP2 methylation of tissue, feces, and blood detection in colorectal cancer development.

The susceptibility of secreted frizzled-related protein 2 (SFRP2) methylation in colorectal cancer (CRC) has been studied previously. The aim of this study was to determine the risk sizes and variation trends of SFRP2 methylation in CRC development in Chinese populations. Subgroup meta-analysis and the least-squares curve-fitting method were carried out to analyze the risk of SFRP2 methylation in tissue, feces, and blood detection from 2221 samples, including a total of 1103 cases of CRC, 459 cases of adenoma, 257 cases of polyps, and 402 controls. The data showed that odds ratios (95% confidence intervals) between CRC and controls for tissue, feces, and blood detection were 334.01 (104.42-1068.39), 63.76 (20.62-197.63), and 133.75 (18.32-976.32), respectively. There were also significant differences between tissue and feces or blood as well as between feces and blood methylation frequency. These results showed that the risk size in tissue was much greater than that in feces and that in blood. The results pointed out that three curves in tissue, feces, and blood detection described the variation trends of methylation incidence from the control to polyp, to adenoma and to CRC, and that the variation trend of the risk size of SFRP2 methylation was synchronized with the histological evolution process of CRC. The variation trend of the risk size of SFRP2 methylation incidence is consistent with the histological evolution process of CRC. The susceptibility to SFRP2 methylation is an important biomarker in the study of early diagnosis of CRC and high-risk patients.

Transarterial chemoembolization versus hepatic resection in hepatocellular carcinoma treatment: a meta-analysis.

BACKGROUND: A number of cohort studies have compared the outcomes of transarterial chemoembolization (TACE) and hepatic resection (HR) in the treatment of hepatocellular carcinoma (HCC). However, the effect of TACE versus HR remains controversial. Therefore, we conducted a meta-analysis to assess the effectiveness of TACE and HR in HCC treatment. MATERIALS AND METHODS: PubMed, Embase, Web of Science, Scopus, ClinicalTrials.gov, and Cochrane library were searched from their inception until February 27, 2015 for relevant studies. The literature search was updated on May 25, 2015. Eligible studies were cohort studies comparing the survival outcomes between HCC patients undergoing TACE and HR. The primary outcome was overall survival (OS). Secondary outcomes were the recurrence rate and prognostic factors for OS. The risk ratio (RR) was used for the meta-analysis and was expressed with 95% confidence intervals (CIs). RESULTS: This meta-analysis included eleven cohort studies with 6,297 patients, all treated with TACE or HR. Pooled estimates showed that, compared with TACE, HR significantly improved the 3-year OS (RR =0.77; 95% CI, 0.63-0.93; P=0.009). TACE and HR had similar effects on OS after 1 year (RR =0.94; 95% CI, 0.86-1.01; P=0.103), 2 years (RR =0.50; 95% CI, 0.21-1.19; P=0.114), 4 years (RR =0.61; 95% CI, 0.58-1.10; P=0.174), and 5 years (RR =0.77; 95% CI, 0.59-1.01; P=0.06). There was no significant difference between the 3-year (RR =1.31; 95% CI, 0.65-2.64; P=0.457) and 5-year recurrence rates (RR =1.14; 95% CI, 0.69-1.89; P=0.597) in the TACE and HR groups. Age (>65 vs ≤65 years; hazard ratio =0.99; 95% CI, 0.98-1.00; P=0.000), sex (male vs female; hazard ratio =0.79; 95% CI, 0.65-0.96; P=0.02), treatment method (TACE vs HR; hazard ratio =1.90; 95% CI, 1.46-2.46; P=0.000), and Eastern Cooperative Oncology Group performance score (≥1 vs 0; hazard ratio =1.69; 95% CI, 1.22-2.33; P=0.002) were independent predictors for OS. CONCLUSION: This meta-analysis suggests that the TACE and HR likely have similar effects in the treatment of HCC patients in terms of OS and recurrence rate. However, this conclusion should be interpreted cautiously due to the presence of further subgroup analyses with respect to outcomes in patients with different liver statuses (Barcelona Clinic Liver Cancer stage A or stage B).

Synergistic effects of snail and quercetin on renal cell carcinoma Caki-2 by altering AKT/mTOR/ERK1/2 signaling pathways.

Renal cell carcinoma has become the most common subtype of kidney cancer, and has the highest propensity to manifest as metastatic disease. Because of lack of knowledge in events that correlated with tumor cell migration and invasion, few therapeutic options are available. Therefore, in current study, we explore the anti-tumoral effect of a potential chemopreventive natural product, quercetin, combined with anti-sense oligo gene therapy (inhibiting Snail gene). We found that either one of them had the remarkable effects in suppressing cell proliferation and migration, inducing cell cycle arrest and apoptosis in a ccRCC cell line, Caki-2 cells. The combination of both means provides even strong suppressive effects toward these ccRCC cells. Our study, for the first time, provides the possibility of using a novel treatment for renal cancer, by combining natural product and gene therapy.

Antiproliferative activity of rosamultic acid is associated with induction of apoptosis, cell cycle arrest, inhibition of cell migration and caspase activation in human gastric cancer (SGC-7901) cells.

BACKGROUND: Gastric cancer is the second leading cause of cancer related deaths after lung cancer globally. Among natural products, natural triterpenes represent a structurally diverse group of organic compounds with potent antitumor activity. PURPOSE: The objective of the present research work demonstrated the antiproliferative and apoptotic activity of rosamultic acid, a natural triterpenoid, in human gastric cancer (SGC-7901) cells. Its effect on cellular morphology, cell cycle arrest, DNA fragmentation and expression levels of caspase-3, caspase-8 and caspase-9 were also determined. METHODS: Antiproliferative activity of rosamultic acid was evaluated by MTT assay. Phase contrast, fluorescence microscopy as well as flow cytometry using Hoechst 33342, acridine orange/ethidium bromide and Annexin V-FITC as cellular probes were used to evaluate the induction of apoptosis by rosamultic acid. Protein level expressions were analyzed by western blot analysis. RESULTS: The results revealed that rosamultic acid induced dose-dependent as well as time dependent cytotoxic effects in SGC-7901 gastric cancer cells. It also led to a reduction in clonogenic activity along with inhibiting the cell migration. Characteristic features of apoptosis induced by rosamultic acid were observed and quantified. Cell cycle arrest at sub-G1 phase was induced by rosamultic acid along with downregulation of expression levels of CDK4, CDK6 and cyclin D1. Rosamultic acid also significantly led to the activation of caspase-3, -8 and -9 during the 48 h treatment along with cleaving PARP in a dose-dependent manner. DNA fragmentation following rosamultic acid treatment was also observed in these cells. CONCLUSION: The current study strongly reveals that rosamultic acid inhibits gastric cancer proliferation by inducing apoptosis mediated through cell cycle arrest, downregulation of cell cycle related protein expressions, inhibition of cell migration, DNA damage, and activation of caspases.

miR-148b reverses cisplatin-resistance in non-small cell cancer cells via negatively regulating DNA (cytosine-5)-methyltransferase 1(DNMT1) expression.

BACKGROUND: The emergence of drug resistance in cancer patients limits the success rate of clinical chemotherapy. MicroRNAs (miRNAs) may play a role in chemoresistance and may be involved in modulating of some drug resistance-related pathways in cancer cells. In this study, the involvement of microRNA-148b (miR-148b) and its roles in the development of chemoresistance in lung cancer are determined. METHODS: This study was performed in two lung cancer cell lines (A549 and SPC-A1). The levels of miR-148b and DNMT1 mRNA expression were determined by using Quantitative Real-Time PCR. Proteins of DNMTs are represented by western blot assay. Cell viability was assessed by MTT assay. Cell apoptosis was evaluated using flow cytometry. RESULTS: The data showed a down-regulated of miR-148b expression and evaluated methyltransferases (DNMTs) expression in cisplatin-resisted human non-small cell lung cancer (NSCLC) cell line-A549/DDP and SPC-A1/DDP compared with their parental A549 and SPC-A1 cell line. In transfection experiments, miR-148b mimics reduced the DNMT1 expression, as well as enhanced the sensitivity of cells to cisplatin and cisplatin-induced apoptosis in A549/DDP or SPC-A1/DDP cells. While miR-148b inhibitor increased DNMT1 expression, as well as attenuated the sensitivity of cells to cisplatin in A549 and SPC-A1 cells. miR-148b was showed to exert negative effect on DNMT1 expression by targeting its 3'UTR in A549/DDP and A549 cells. Importantly, silenced DNMT1 increases cisplatin sensitivity of A549/DDP cells and over-expressed DNMT1 reverses pro-apoptosis effect of miR-148b mimic. CONCLUSIONS: miR-148b reverses cisplatin-resistance in non-small cell cancer cells via negatively regulating DNMT1 expression.

Insights into the application of let-7 family as promising biomarker in cancer screening.

Cancer is a leading cause of death worldwide with its low 5-year survival rate. Studies on the accuracy of let-7 family for human cancers have inconsistent conclusions, leading us to conduct this meta-analysis. This meta-analysis comprised of 11 studies from eight articles involving 805 cancer patients and 483 controls. The pooled parameters were as follows: sensitivity, 77 % (95 % confidence interval (CI) 73-81 %); specificity, 80 % (95 % CI 68-88 %); positive likelihood ratio (PLR), 3.8; negative likelihood ratio (NLR), 0.29; and diagnostic odds ratio (DOR) 13.0. In addition, we plotted the SROC and calculated the area under the curve (AUC) of 0.81 (95 % CI 0.78-0.84), which indicated a relatively high descriptive accuracy. In summary, our data suggested that let-7 family might be applied in noninvasive screening tests for human cancers, which needed to be validated in further large-scale studies.

Association between cytochrome P450 1A1 (CYP1A1) gene polymorphisms and the risk of renal cell carcinoma: a meta-analysis.

Cytochrome P450 1A1 (CYP1A1) usually metabolizes carcinogens to their inactive derivatives but occasionally converts the chemicals to more potent carcinogens. To date, many studies have evaluated the association between the CYP1A1 MspI and Ile462Val polymorphisms and renal cell carcinoma (RCC) risk, but the results have been conflicting. To more precisely evaluate the potential association, we carried out a meta-analysis of seven published case-control studies. The meta-analysis indicated that the MspI polymorphism was associated with an increased RCC risk (allele model: OR = 1.49, 95%CI 1.03-2.16; homozygous model: OR = 1.64, 95%CI 1.13-2.40; dominant model: OR = 1.72, 95%CI 1.07-2.76). No significant associations were found for the Ile462Val polymorphism for all genetic models. When stratified by smoking status, smokers carrying the variant Vt and Val allele were more susceptible to RCC (Vt allele: OR = 3.37, 95%CI = 2.24-5.06; Val allele: OR = 2.07, 95%CI = 1.34-3.19). These data indicate that the CYP1A1 MspI polymorphism significantly increased RCC risk, while the Ile462Val polymorphism was not associated with RCC. Among smokers, individuals with the CYP1A1 Vt allele and Val allele showed a significantly increased risk of RCC. More well-designed studies with larger samples are warranted to show the underlying mechanisms of CYP1A1 in the development of RCC.

Bufalin Induces Mitochondria-Dependent Apoptosis in Pancreatic and Oral Cancer Cells by Downregulating hTERT Expression via Activation of the JNK/p38 Pathway.

Bufalin, a digoxin-like active component of the traditional Chinese medicine Chan Su, exhibits potent antitumor activities in many human cancers. Bufalin induces mitochondria-dependent apoptosis in cancer cells, but the detailed molecular mechanisms are largely unknown. hTERT, the catalytic subunit of telomerase, protects against mitochondrial damage by binding to mitochondrial DNA and reducing mitochondrial ROS production. In the present study, we investigated the effects of bufalin on the cell viability, ROS production, DNA damage, and apoptosis of CAPAN-2 human pancreatic and CAL-27 human oral cancer cells. Bufalin reduced CAPAN-2 and CAL-27 cell viability with IC50 values of 159.2 nM and 122.6 nM, respectively. The reduced cell viability was accompanied by increased ROS production, DNA damage, and apoptosis and decreased expression of hTERT. hTERT silencing in CAPAN-2 and CAL-27 cells by siRNA resulted in increased caspase-9/-3 cleavage and DNA damage and decreased cell viability. Collectively, these data suggest that bufalin downregulates hTERT to induce mitochondria-dependent apoptosis in CAPAN-2 and CAL-27 cells. Moreover, bufalin increased the phosphorylation of JNK and p38-MAPK in CAPAN-2 and CAL-27 cells, and blocking the JNK/p38-MAPK pathway using the JNK inhibitor SP600125 or the p38-MAPK inhibitor SB203580 reversed bufalin-induced hTERT downregulation. Thus, the JNK/p38 pathway is involved in bufalin-induced hTERT downregulation and subsequent induction of apoptosis by the mitochondrial pathway.