Molecular profile of the BCL2 family of the apoptosis related genes in breast cancer cells after treatment with cytotoxic/cytostatic drugs

Pigmented Microbial Extract (PMB) from Exiguobacterium Species MB2 Strain (PMB1) and Bacillus subtilis Strain MB1 (PMB2) Inhibited Breast Cancer Cells Growth In Vivo and In Vitro

Breast cancer (BC) continues to be one of the major causes of cancer deaths in women. Progress has been made in targeting hormone and growth factor receptor-positive BCs with clinical efficacy and success. However, little progress has been made to develop a clinically viable treatment for the triple-negative BC cases (TNBCs). The current study aims to identify potent agents that can target TNBCs. Extracts from microbial sources have been reported to contain pharmacological agents that can selectively inhibit cancer cell growth. We have screened and identified pigmented microbial extracts (PMBs) that can inhibit BC cell proliferation by targeting legumain (LGMN). LGMN is an oncogenic protein expressed not only in malignant cells but also in tumor microenvironment cells, including tumor-associated macrophages. An LGMN inhibition assay was performed, and microbial extracts were evaluated for in vitro anticancer activity in BC cell lines, angiogenesis assay with chick chorioallantoic membrane (CAM), and tumor xenograft models in Swiss albino mice. We have identified that PMB from the Exiguobacterium (PMB1), inhibits BC growth more potently than PMB2, from the Bacillus subtilis strain. The analysis of PMB1 by GC-MS showed the presence of a variety of fatty acids and fatty-acid derivatives, small molecule phenolics, and aldehydes. PMB1 inhibited the activity of oncogenic legumain in BC cells and induced cell cycle arrest and apoptosis. PMB1 reduced the angiogenesis and inhibited BC cell migration. In mice, intraperitoneal administration of PMB1 retarded the growth of xenografted Ehrlich ascites mammary tumors and mitigated the proliferation of tumor cells in the peritoneal cavity in vivo. In summary, our findings demonstrate the high antitumor potential of PMB1.

Long Noncoding RNAs in Taxane Resistance of Breast Cancer

Breast cancer is a common cancer in women and a leading cause of mortality. With the early diagnosis and development of therapeutic drugs, the prognosis of breast cancer has markedly improved. Chemotherapy is one of the predominant strategies for the treatment of breast cancer. Taxanes, including paclitaxel and docetaxel, are widely used in the treatment of breast cancer and remarkably decrease the risk of death and recurrence. However, taxane resistance caused by multiple factors significantly impacts the effect of the drug and leads to poor prognosis. Long noncoding RNAs (lncRNAs) have been shown to play a significant role in critical cellular processes, and a number of studies have illustrated that lncRNAs play vital roles in taxane resistance. In this review, we systematically summarize the mechanisms of taxane resistance in breast cancer and the functions of lncRNAs in taxane resistance in breast cancer. The findings provide insight into the role of lncRNAs in taxane resistance and suggest that lncRNAs may be used to develop therapeutic targets to prevent or reverse taxane resistance in patients with breast cancer.

Gene expression of angiogenesis and apoptotic factors in female BALB/c mice with breast cancer after eight weeks of aerobic training

OBJECTIVES

Breast cancer is the most common cancer in women, caused by a disorder in the angiogenesis and apoptosis process. Exercise can affect the process of angiogenesis and apoptosis in the tumor tissue. Thus, the aim of the present study was to investigate the changes in angiogenesis and apoptotic factors in mice with breast cancer after 8 weeks of exercise training.

MATERIALS AND METHODS

Sixteen females BALB/c mice (age: 3-5 weeks and weight: 17.1 ± 0.1 g) with breast cancer were randomly divided into two groups of aerobic training and control. The aerobic training included 8 weeks and 5 sessions per week of running with an intensity of 14-20 m.min-1. HIF-1α, VEGF, miR-21 and cytochrome C, Apaf-1, caspase-9, and caspase-3 gene expressions were examined by real-time PCR. Repeated measures ANOVA, Bonferroni's post hoc test, and independent samples t-test were used to analyze the data (P<0.05).

RESULTS

The results showed that aerobic training reduced the growth of tumor volume and significantly reduced miR-21 gene expression. Aerobic training also significantly increased the gene expression of HIF-1α, cytochrome C, Apaf-1, caspase-9, and caspase-3, while changes in VEGF gene expression were not statistically significant.

CONCLUSION

It appears that aerobic exercise training reduces tumor size and ameliorates breast cancer by reducing miR-21 gene expression, suppressing the apoptosis process, and reducing angiogenesis.

A coordinated ruthenium-rifampicin complex reprogramming the colon carcinoma micro-environment mediated by modulation of p53/AkT/mTOR/VEGF pathway

WHO suggests that colon cancer incidences are rising steadily, propelling researchers to search for novel chemotherapeutic options. Metal-based chemotherapy is a potential forte to explore ruthenium-based complexes, exhibiting the capability to influence a variety of cellular targets. We discovered the chemotherapeutic effects of ruthenium-rifampicin complex on HT-29 and HCT-116 human colorectal cell lines and on a chemically developed murine colorectal cancer model. Complex was synthesized and characterized by analytical techniques and evaluation of antioxidant potential along with DNA binding capabilities. The complex minimizes cellular propagation and initiates apoptotic events in the colon cancer cell lines of HT-29 and HCT-116. The results of the in vivo study suggest that the complex has been successful in minimizing the wide spectrum of aberrant crypt foci and hyperplastic lesions, as well as encouraging elevated amounts of CAT, SOD and glutathione. Along with that, p53 could be modulated by the ruthenium-rifampicin complex to interfere with apoptosis in colon carcinoma, initiated by the intrinsic apoptotic trail facilitated through Bcl2 and Bax, thus controlling the Akt/mTOR/VEGF pathway coupled through the WNT/β-catenin trail. Ruthenium-rifampicin chemotherapy could interrupt, retract or interrupt the progression of colorectal cancer through modifying intrinsic apoptosis including the antiangiogenic pathway, thereby achieving the function of a potential contender in chemotherapy in the near future.

Ursolic Acid Regulates Cell Cycle and Proliferation in Colon Adenocarcinoma by Suppressing Cyclin B1

Aims: The biological functions of cyclin B1 (CCNB1) in colon adenocarcinoma (COAD) will be explored in this study. Furthermore, the therapeutic effects and potential molecular mechanisms of ursolic acid (UA) in COAD cells will also be investigated in vitro.

Methods: COAD data were obtained from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Differentially expressed genes (DEGs) were determined with differential analysis. The biological functions of CCNB1 were analyzed through the GeneCards, the Search Tool for the Retrieval of Interacting Genes (STRING), and the Database for Annotation, Visualization, and Integrated Discovery (DAVID) databases. Therapeutic effects of UA on COAD cell lines HCT-116 and SW-480 were analyzed by CCK-8 and high-content screening (HCS) imaging assay. Flow cytometry was utilized to detect cell cycle changes of SW-480 and HCT-116 cells. Levels of mRNA and expression proteins of HCT-116, SW-480, and normal colon epithelial cells NCM-460 were determined by qRT-PCR and western blot.

Results: CCNB1 was highly expressed and acted as an oncogene in COAD patients. CCNB1 and its interacting genes were significantly enriched in the cell cycle pathway. UA effectively inhibited the proliferation and injured COAD cells. In addition, UA arrested cell cycle of COAD cells in S phase. With regard to the molecular mechanisms of UA, we demonstrated that UA can significantly downregulate CCNB1 and its interacting genes and proteins, including CDK1, CDC20, CCND1, and CCNA2, which contributed to cell cycle blocking and COAD treatment.

Conclusion: Results from this study revealed that UA possesses therapeutic effects on COAD. The anti-COAD activities of UA are tightly related to suppression of CCNB1 and its interacting targets, which is crucial in abnormal cell cycle process.

Tamoxifen and the PI3K Inhibitor: LY294002 Synergistically Induce Apoptosis and Cell Cycle Arrest in Breast Cancer MCF-7 Cells

Breast cancer is considered as one of the most aggressive types of cancer. Acquired therapeutic resistance is the major cause of chemotherapy failure in breast cancer patients. To overcome this resistance and to improve the efficacy of treatment, drug combination is employed as a promising approach for this purpose. The synergistic cytotoxic, apoptosis inducing, and cell cycle effects of the combination of LY294002 (LY), a phosphatidylinositide-3-kinase (PI3K) inhibitor, with the traditional cytotoxic anti-estrogen drug tamoxifen (TAM) in breast cancer cells (MCF-7) were investigated. LY and TAM exhibited potent cytotoxic effect on MCF-7 cells with IC50 values 0.87 µM and 1.02 µM. The combination of non-toxic concentration of LY and TAM showed highly significant synergistic interaction as observed from isobologram (IC50: 0.17 µM, combination index: 0.18, colony formation: 9.01%) compared to untreated control. The percentage of early/late apoptosis significantly increased after treatment of MCF-7 cells with LY and TAM combination: 40.3%/28.3% (p < 0.001), compared to LY single treatment (19.8%/11.4%) and TAM single treatment (32.4%/5.9%). In addition, LY and TAM combination induced the apoptotic genes Caspase-3, Caspase-7, and p53, as well as p21 as cell cycle promotor, and significantly downregulated the anti-apoptotic genes Bcl-2 and survivin. The cell cycle assay revealed that the combination induced apoptosis by increasing the pre-G1: 28.3% compared to 1.6% of control. pAKT and Cyclin D1 protein expressions were significantly more downregulated by the combination treatment compared to the single drug treatment. The results suggested that the synergistic cytotoxic effect of LY and TAM is achieved by the induction of apoptosis and cell cycle arrest through cyclin D1, pAKT, caspases, and Bcl-2 signaling pathways.

Changes in apoptosis-related gene expression and cytokine release in breast cancer cells treated with CpG-loaded magnetic PAMAM nanoparticles

CpG-oligodeoxynucleotide (CpG-ODN) can function as an immune adjuvant. Previously, we showed that stimulation of breast cancer cells with CpG-ODN conjugated with PAMAM dendrimer-coated magnetic nanoparticles (DcMNPs) has induced apoptosis. The aim of the current study was to evaluate the expression levels of some apoptosis-regulating genes in several human breast cancer cells treated with CpG/DcMNPs. Treated MDA-MB231 cells showed an increase in Noxa and Bax gene expression levels, whereas the expression level of Survivin decreased. Similarly, Noxa gene was overexpressed in treated MCF7 cells. In treated SKBR3 cells, a decline in the c-Flip mRNA level was determined. Furthermore, release of cytokines, IL-6, IL-10, and TNF-α, was determined in cell culture supernatants. CpG/DcMNP treatment leads to an increase in the release of IL-6 in MDA-MB231 and SKBR3 cells, whereas release of IL-10 and TNF-α did not change significantly. It is indicated that CpG-ODN may show its cytotoxic effect by regulating the expression of apoptosis-related genes and the release of cytokine in breast cancer cells.

Cyclooxygenase-2 in tumor-associated macrophages promotes breast cancer cell survival by triggering a positive-feedback loop between macrophages and cancer cells

Tumor-associated macrophages (TAMs) play an important role in cancer cell survival, however, the mechanism of which remains elusive. In this study, we found that COX-2 was abundantly expressed in breast TAMs, which was correlated to poor prognosis in breast cancer patients. Ectopic over-expression of COX-2 in TAMs enhanced breast cancer cell survival both in vitro and in vivo. COX-2 in TAMs was determined to be essential for the induction and maintenance of M2-phenotype macrophage polarity. COX-2⁺ TAMs promoted breast cancer cell proliferation and survival by increasing Bcl-2 and P-gp and decreasing Bax in cancer cells. Furthermore, COX-2 in TAMs induced the expression of COX-2 in breast cancer cells, which in turn promoted M2 macrophage polarization. Inhibiting PI3K/Akt pathway in cancer cells suppressed COX-2⁺ TAMs-induced cancer cell survival. These findings suggest that COX-2, functions as a key cancer promoting factor by triggering a positive-feedback loop between macrophages and cancer cells, which could be exploited for breast cancer prevention and therapy.

Bcl-2 expression predicts sensitivity to chemotherapy in breast cancer: a systematic review and meta-analysis

Background

Numerous studies have yielded inconclusive results regarding the relationship between anti-apoptotic protein Bcl-2 expression and the sensitivity to chemotherapy in the patients with breast cancer. The purpose of the current study was therefore to elaborate their relationship.

Methods, findings

A total of 23 previously published eligible studies involving 2,467 cases were identified and included in this meta-analysis. Negative Bcl-2 expression was associated with good chemotherapy response in breast cancer patients (total objective response [OR]: risk ratio [RR] = 1.16, 95% confidence interval [CI] = 1.02-1.32, p = 0.026; total complete response [CR]: RR = 1.67, 95% CI = 1.24-2.24, p = 0.001; pathological CR: RR = 1.92, 95% CI = 1.38-2.69, p < 0.001). In further stratified analyses, this association remained for sub-groups of response in neoadjuvant chemotherapy setting, especially pathological CR. Besides, negative Bcl-2 expression was significantly associated with good OR and pathological CR in anthracycline-based chemotherapy subgroup. Furthermore, there were significant links between negative Bcl-2 expression and taxane-based chemotherapy with pathological CR, but not OR.

Conclusion

The results of the present meta-analysis suggest that Bcl-2 expression is a predictive factor for chemotherapy sensitivity in breast cancer patients. They could also potentially benefit further clinical treatment for breast cancers.

Salinomycin increases chemosensitivity to the effects of doxorubicin in soft tissue sarcomas

Background

Chemotherapy for soft tissue sarcomas remains unsatisfactory due to their low chemosensitivity. Even the first line chemotherapeutic agent doxorubicin only yields a response rate of 18-29%. The antibiotic salinomycin, a potassium ionophore, has recently been shown to be a potent compound to deplete chemoresistant cells like cancer stem like cells (CSC) in adenocarcinomas. Here, we evaluated the effect of salinomycin on sarcoma cell lines, whereby salinomycin mono- and combination treatment with doxorubicin regimens were analyzed.

Methods

To evaluate the effect of salinomycin on fibrosarcoma, rhabdomyosarcoma and liposarcoma cell lines, cells were drug exposed in single and combined treatments, respectively. The effects of the corresponding treatments were monitored by cell viability assays, cell cycle analysis, caspase 3/7 and 9 activity assays. Further we analyzed NF-κB activity; p53, p21 and PUMA transcription levels, together with p53 expression and serine 15 phosphorylation.

Results

The combination of salinomycin with doxorubicin enhanced caspase activation and increased the sub-G1 fraction. The combined treatment yielded higher NF-κB activity, and p53, p21 and PUMA transcription, whereas the salinomycin monotreatment did not cause any significant changes.

Conclusions

Salinomycin increases the chemosensitivity of sarcoma cell lines - even at sub-lethal concentrations - to the cytostatic drug doxorubicin. These findings support a strategy to decrease the doxorubicin concentration in combination with salinomycin in order to reduce toxic side effects.

Neem leaf extract inhibits mammary carcinogenesis by altering cell proliferation, apoptosis, and angiogenesis

Plant-based medicines are useful in the treatment of cancer. Many breast cancer patients use complementary and alternative medicine in parallel with conventional treatments. Neem is historically well known in Asia and Africa as a versatile medicinal plant with a wide spectrum of biological activities. The experiments reported herein determined whether the administration of an ethanolic fraction of Neem leaf (EFNL) inhibits progression of chemical carcinogen-induced mammary tumorigenesis in rat models. Seven-week-old female Sprague Dawley rats were given a single intraperitoneal injection of N-methyl-N-nitrosourea (MNU). Upon the appearance of palpable mammary tumors, the rats were divided into vehicle-treated control groups and EFNL-treated groups. Treatment with EFNL inhibited MNU-induced mammary tumor progression. EFNL treatment was also highly effective in reducing mammary tumor burden and in suppressing mammary tumor progression even after the cessation of treatment. Further, we found that EFNL treatment effectively upregulated proapoptotic genes and proteins such as p53, B cell lymphoma-2 protein (Bcl-2)-associated X protein (Bax), Bcl-2-associated death promoter protein (Bad) caspases, phosphatase and tensin homolog gene (PTEN), and c-Jun N-terminal kinase (JNK). In contrast, EFNL treatment caused downregulation of anti-apoptotic (Bcl-2), angiogenic proteins (angiopoietin and vascular endothelial growth factor A [VEGF-A]), cell cycle regulatory proteins (cyclin D1, cyclin-dependent kinase 2 [Cdk2], and Cdk4), and pro-survival signals such as NFκB, mitogen-activated protein kinase 1 (MAPK1). The data obtained in this study demonstrate that EFNL exert a potent anticancer effect against mammary tumorigenesis by altering key signaling pathways.

Targeting IRAK1 as a therapeutic approach for myelodysplastic syndrome

Myelodysplastic syndromes (MDSs) arise from a defective hematopoietic stem/progenitor cell. Consequently, there is an urgent need to develop targeted therapies capable of eliminating the MDS-initiating clones. We identified that IRAK1, an immune-modulating kinase, is overexpressed and hyperactivated in MDSs. MDS clones treated with a small molecule IRAK1 inhibitor (IRAK1/4-Inh) exhibited impaired expansion and increased apoptosis, which coincided with TRAF6/NF-κB inhibition. Suppression of IRAK1, either by RNAi or with IRAK1/4-Inh, is detrimental to MDS cells, while sparing normal CD34(+) cells. Based on an integrative gene expression analysis, we combined IRAK1 and BCL2 inhibitors and found that cotreatment more effectively eliminated MDS clones. In summary, these findings implicate IRAK1 as a drugable target in MDSs.

Apoptosis, angiogenesis, inflammation, and oxidative stress: basic interactions in patients with early and metastatic breast cancer

PURPOSE

Breast cancer (BC) is a complex, multi-stage disease involving deregulation of different signaling cascades. The present study was conducted to determine the extent of apoptosis, angiogenesis, inflammation, and oxidative stress in patients with different stages of BC as an approach to disease biological behavior. Therefore, plasma levels of soluble (s) Fas, bcl-2 as antiapoptotic indices; interleukin (IL)-8, tumor necrosis factor (TNF)-α as apoptotic, inflammatory, angiogenic indices; lipid peroxides (LPO), nitric oxide (NO) as oxidative stress and angiogenic indices were measured in patients with BC.

METHODS

Thirty-seven newly diagnosed patients with BC, 30 patients with benign breast masses, and 30 healthy controls were recruited. Plasma levels of sFas, bcl-2, IL-8, and TNF-α were measured by immunosorbent assay kits and LPO and NO by chemical methods.

RESULTS

Plasma sFas and LPO were significantly higher in BC patients versus benign breast masses and healthy controls (P < 0.0001). Bcl-2, IL-8, TNF-α, and NO were significantly higher in benign breast masses (P < 0.0001, P < 0.037, P < 0.0001, P < 0.001) and BC (P < 0.0001) versus controls and in BC versus benign breast masses (P < 0.0001). sFas, bcl-2, IL-8, TNF-α, LPO, and NO were increased with advanced tumor stages. There were positive correlations between sFas, bcl-2, IL-8 TNF-α, LPO, and NO.

CONCLUSIONS

BC tumor cells overexpress bcl-2 and sFas to secure their outgrowth and survival. However, this coincides with activation of physiologic regulatory mechanisms, as increased IL-8, TNF-α, LPO, and NO, which try to stop tumor cells by inducing apoptosis. Outcompeting of these mechanisms result in tumor progression as IL-8, TNF-α, and NO are also angiogenic stimulators.

G1P3, an interferon- and estrogen-induced survival protein contributes to hyperplasia, tamoxifen resistance and poor outcomes in breast cancer

Hormonally regulated survival factors can have an important role in breast cancer. Here we elucidate G1P3, a survival protein induced by interferons (IFNs), as a target of estrogen signaling and a contributor to poor outcomes in estrogen receptor-positive (ER(+)) breast cancer. Compared with normal breast tissue, G1P3 was upregulated in the malignant epithelium (50 × higher) and was induced by estrogen ex vivo. In accord with its overexpression in early stages of breast cancer (hyperplasia and ductal carcinoma in situ), in morphogenesis assays G1P3 enhanced the survival of MCF10A acinar luminal cells causing hyperplasia by suppressing detachment-induced loss of mitochondrial potential and apoptosis (anoikis). In cells undergoing anoikis, G1P3 attenuated the induction of Bim protein, a proapoptotic member of the Bcl-2 family and reversed the downmodulation of Bcl-2 protein. Downregulation of G1P3 induced spontaneous apoptosis in BT-549 breast cancer cells and significantly reduced the growth of ER(+) breast cancer cell MCF7 (P≤0.01), further suggesting its prosurvival activity. In agreement with its induction by estrogen, G1P3 antagonized tamoxifen, an inhibitor of ER in MCF7 cells. More importantly, elevated expression of G1P3 was significantly associated with decreased relapse-free and overall survival in ER(+) breast cancer patients (P≤0.01). Our studies suggest that elevated expression of G1P3 may perturb canonical tumor-suppressing activity of IFNs partly by affecting the balance of pro- and antiapoptotic members of Bcl-2 family proteins, leading to breast cancer development and resistance to therapies.

Proliferation-inhibiting and apoptosis-inducing effects of ursolic acid and oleanolic acid on multi-drug resistance cancer cells in vitro

OBJECTIVE

To investigate the proliferation-inhibiting and apoptosis-inducing effects of ursolic acid (UA) and oleanolic acid (OA) on multi-drug resistance (MDR) cancer cells in vitro.

METHODS

UA and OA in different concentrations (0-100 μmol/L) were added separately to cultures of different cancer cell lines, including the human colon cancer cell lines SW480 and SW620, human acute myelocytic leukemia cancer cell lines HL60 and HL60/ADR, human chronic myelogenous leukemia cell lines K562 and K562/ADR, and the human breast cancer cell lines MCF-7 and MCF-7/ADR. Effects of UA and OA on cell proliferation were detected by 3-(4,5-dimethyl-2-thiazole)-2-5-biphenly-tetrazole bromide (MTT) method and effects on cell apoptosis were tested by flow cytometry (FCM) and Western blot at 24, 48, and 72 h after treatment.

RESULTS

Both UA and OA showed significant inhibition on parent and MDR cell lines in a time- and concentration-dependent manner; the drug-resistant multiple of them on K562 and K562/ADR as well as on HL60 and HL60/ADR was 1; the effects of UA were better than those of OA in inhibiting cell growth of solid colonic cancer and breast cancer. After SW480 cells were treated by UA at the concentrations of 0-40 μmol/L for 48 h, FCM showed that annexin V (AV) positive cells and hypodiploid peak ratio increased along with the increase in the drug's concentrations; and Western blot found that expressions of Bcl-2, Bcl-xL and survivin decreased in a concentration-dependent manner.

CONCLUSIONS

Both UA and OA have antitumor effects on cancer cells with MDR, and the optimal effect is shown by UA on colonic cancer cells. Also, UA shows cell apoptosis-inducing effect on SW480, possibly by way of down-regulating the expressions of apoptosis antagonistic proteins, Bcl-2, Bcl-xL, and survivin.

The Differential Effect of Toxoplasma Gondii Infection on the Stability of BCL2-Family Members Involves Multiple Activities

The regulation of mitochondrial permeability, a key event in the initiation of apoptosis is governed by the opposing actions of the pro- and anti-apoptotic members of the BCL2-family of proteins. The BCL2-family can be classified further based on the number of BCL-homology (BH) domains they encode. Pathogen mediated modulation of BCL2-family members play a significant role in their ability to affect the apoptotic pathways in the infected host cell. The protozoan parasite Toxoplasma gondii establishes a profound blockade of apoptosis noted by a requirement for host NFκB activity and correlating with the selective degradation of pro-apoptotic BCL2-family members. In this study, we explore the potential activities associated with the inherent stability of the anti-apoptotic BCL2 as well as the selective degradation of the pro-apoptotic proteins BAX, BAD, and BID. We find that multiple activities govern the relative stability of BCL2-family members suggesting a complex and balanced network of stability-enhancing and–destabilizing activities are perturbed by parasite infection. The data leave open the possibility for both parasite induced host activities as well as the direct consequence of parasite effectors in governing the relative levels of BCL2-proteins in the course of infection.

Klotho inhibits growth and promotes apoptosis in human lung cancer cell line A549

Background

Klotho, as a new anti-aging gene, can shed into circulation and act as a multi-functional humoral factor that influences multiple biological processes. Recently, published studies suggest that klotho can also serve as a potential tumor suppressor. The aim of this study is to investigate the effects and possible mechanisms of action of klotho in human lung cancer cell line A549.

Methods

In this study, plasmids encoding klotho or klotho specific shRNAs were constructed to overexpress or knockdown klotho in vitro. A549 cells were respectively treated with pCMV6-MYC-KL or klotho specific shRNAs. The MTT assay was used to evaluate the cytotoxic effects of klotho and flow cytometry was utilized to observe and detect the apoptosis of A549 cells induced by klotho. The activation of IGF-1/insulin signal pathways in A549 cells treated by pCMV6-MYC-KL or shRNAs were evaluated by western blotting. The expression levels of bcl-2 and bax transcripts were evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR).

Results

Overexpression of klotho reduced the proliferation of lung cancer A549 cells, whereas klotho silencing in A549 cells enhanced proliferation. Klotho did not show any effects on HEK-293 cells. Klotho overexpression in A549 cells was associated with reduced IGF-1/insulin-induced phosphorylation of IGF-1R (IGF-1 receptor)/IR (insulin receptor) (P < 0.01). Overexpression of klotho can promote the apoptosis of A549 cells (P < 0.01). Overexpression of klotho, a bcl family gene bax, was found up-regulated and bcl-2, an anti-apoptosis gene, was found down-regulated (P < 0.01). In contrast, bax and bcl-2 were found down-regulated (P < 0.05) and up-regulated (P < 0.01), respectively when silencing klotho using shRNAs.

Conclusions

Klotho can inhibit proliferation and increase apoptosis of A549 cells, this may be partly due to the inhibition of IGF-1/insulin pathways and involving regulating the expression of the apoptosis-related genes bax/bcl-2. Thus, klotho can serve as a potential tumor suppressor in A549 cells.

TNF superfamily gene polymorphism as prognostic factor in early breast cancer

PURPOSE

Since apoptosis may play a role in the prognosis of breast cancer, the present study analyzed the polymorphisms of apoptosis-related genes and their impact on the survival of 240 patients with early invasive ductal breast cancer.

METHODS

The genomic DNA was extracted from paraffin-embedded tumor-free tissue or blood, and 12 single nucleotide polymorphisms (SNPs) of 11 apoptosis-related genes in the apoptosis pathway determined using a Sequenom MassARRAY system.

RESULTS

During the median follow-up of 53.4 (range 2.9-205.9) months, 37 relapses and 22 deaths occurred. Among the target polymorphisms, the tumor necrosis factor superfamily member 10 gene polymorphism (TNFSF10 rs1131532) in a recessive model of the T allele and prostaglandin-endoperoxide synthase 2 gene polymorphism (PTGS2 rs5275) in a dominant model of the C allele were associated with survival in a log-rank test. The TT genotype of TNFSF10 (rs1131532) was also significantly correlated with a lower disease-free, distant disease-free, and overall survival in a multivariate analysis (HR = 3.304, 4.757, and 6.459; P = 0.002, 0.001, and 0.009, respectively), while PTGS2 rs5275 was only associated with a higher distant disease-free survival (HR = 0.302; P = 0.041). No clinicopathologic difference was observed according to the genotypes of these two polymorphisms.

CONCLUSION

The TNFSF10 (rs1131532) polymorphism was identified as a possible prognostic factor of survival in patients with operated invasive breast cancer.