Bcl2 family proteins in carcinogenesis and the treatment of cancer

Effects of astragalus injection on different stages of early hepatocarcinogenesis in a two-stage hepatocarcinogenesis model using rats

To clarify the suppressive effects of astragalus injection (AI) on different stages of early hepatocarcinogenesis induced by weak promotion, SD rats initiated with a single intraperitoneal (i.p.) injection of N-diethylnitrosamine (DEN) at 200 mg/kg body weight and promoted with 0.5% piperonyl butoxide (PBO) in diet were repeatedly administered AI at 5 ml/kg body weight/day in the early postinitiation (EPI) or late postinitiation (LPI) period for 2 or 8 weeks, respectively. The number and area of glutathione S-transferase placental form (GST-P)-immunoreactive ⁽⁺⁾ foci tended to increase in the DEN+PBO group compared with the DEN-alone group. Among the PBO-promoted groups, number and area of GST-P⁺ foci did not visibly change in the DEN+PBO+AI-EPI group compared with the DEN+PBO group. In contrast, number and area of GST-P⁺ foci tended to decrease in the DEN+PBO+AI-LPI group compared with the DEN+PBO group. Number of Ki67⁺ cells was increased in the DEN+PBO group compared with the DEN-alone group and was decreased in both AI-administered groups compared with the DEN+PBO group. Gene expression analysis revealed that the DEN+PBO+AI-LPI group showed increased transcript levels of Ccne1, Cdkn1b, Rb1, Bax, Bcl2, Casp3, and Casp9 compared with the DEN+PBO group; however, the DEN+PBO+AI-EPI group did not show changes in the transcript levels of any genes examined compared with the DEN+PBO. These results suggest that AI administration during the LPI period caused weak suppression of hepatocarcinogenesis under weak promotion with a low PBO dose by the mechanism involving facilitation of cell cycle suppression causing G1/S arrest and apoptosis via the mitochondrial pathway. In addition, the results suggest that AI administration during the EPI period has no effect on weakly promoted hepatocarcinogenesis.

In vitro Effect of Recombinant Feline Interferon-Ω (rFeIFN-Ω) on the Primary CanineTransmissible Venereal Tumor Culture

Background: Interferons (IFNs), signaling proteins produced by host cells, are secreted in response to pathogen activity as well as to tumor cells, and display antiviral, antiproliferative, and immunomodulatory effects. Recombinant feline interferon omega (rFeIFN-ω) has in vitro growth inhibition activities on various canine and feline tumor cell lines. Canine transmissible venereal tumor (CTVT) is used as an animal model for immunotherapy due to its specific growth phase. Previous studies have usually focused on the interaction between tumor infiltrating lymphocytes (TILs) and CTVT cells. However, the specific effects of rFeIFN-ω on CTVT cells remains poorly defined.

Aims: The aims of this study, therefore, were to evaluate the in vitro effect of rFeIFN-ω on primary CTVT cells and to study the mRNA expression of apoptotic genes and drug resistance genes.

Materials and Methods: Purified CTVT cells were treated with various concentrations of rFeIFN-ω and the viability of the cultured cells was ascertained at 24, 48, and 72 h post treatment (hpt) and a dose-response curve plotted. The mRNA expression of apoptotic (BAX and BCL-2) and drug resistance (ABCB1 and ABCG2) genes was performed by reverse transcription quantitative real-time PCR at 72 hpt.

Results: rFeIFN-ω displayed an effect against CTVT cell viability, which decreasing viability in a dose-dependent manner within 72 hpt. The relative mRNA expression of BCL-2 was upregulated only at a rFeIFN-ω concentration of 10⁴ IU/100 μl. However, higher concentrations of rFeIFN-ω gave a higher level of relative mRNA expression of ABCB1 transporter gene.

Conclusion: This study provided the information of in vitro effect of rFeIFN-ω on CTVT cell viability in a dose dependent manner, as well as, the alteration of BCL-2 and ABCB1 gene expression after treatment. These results encourage future in vivo studies to evaluate the potential efficacy of this treatment in CTVT cases.

Design, computational studies, synthesis and biological evaluation of thiazole-based molecules as anticancer agents

BACKGROUND

Abolition of cancer warrants effective treatment modalities directed towards specific pathways dysregulated in tumor proliferation and survival. The antiapoptotic Bcl-2 proteins are significantly altered in several tumor types which position them as striking targets for therapeutic intervention. Here we designed, computationally evaluated, synthesized, and biologically tested structurally optimized thiazole-based small molecules as anticancer agents.

METHODS

The virtually designed 200 molecules were subjected to rigorous docking and in silico ADME-Toxicity studies. Out of this, 23 skeletally diverse thiazole-based molecules which passed pan assay interference compounds (PAINS) filter and were synthetically feasible were synthesized in 3 steps using cheap and readily available reagents. The molecules were in vitro evaluated against Bcl-2-Jurkat, A-431 cancerous cell lines and ARPE-19 cell lines. Molecular Dynamics (MD) simulation studies were performed to analyse conformational changes induced by ligand 32 in Bcl-2. Flow cytometry analysis of compound 32 treated Bcl-2 cells was done to check apoptosis.

RESULTS

The molecules exhibited appreciable interactions with Bcl-2 and were having acceptable drug like properties as tested in silico. The multi step synthesis yielded 23 skeletally diverse thiazole-based molecules in up to 80% yield. The molecules simultaneously inhibited Bcl-2 Jurkat cells in vitro without causing detectable toxicity to normal cells (ARPE-19 cells). Among them molecules 32, 50, 53, 57 and 59 showed considerable activities against Bcl-2 Jurkat and A-431cell lines at concentrations ranging from 32-46 μM and 34-52 μM, respectively. The standard doxorubicin exhibited IC₅₀ in Bcl-2 Jurkat and A-431cell lines at 45.87 μM and 42.37 μM, respectively. The molecule 32, almost equipotent in both the cell lines was subjected to molecular dynamics (MD) simulation with Bcl-2 protein (4IEH). It was shown that 32 interacted with protein majorly via hydrophobic interactions and few H-bonding interactions. Fluorescence-activated cell sorting (FACS) analysis established that molecule is dragging cancerous cells towards apoptosis.

DISCUSSION AND CONCLUSION

The chemical intuition was checked by computation coupled with biological results confirmed that thiazole-based hits have the potential to be developed downstream into potent and safer leads against antiapoptotic Bcl-2 cells.

High-Dose Aspirin Reverses Tartrazine-Induced Cell Growth Dysregulation Independent of p53 Signaling and Antioxidant Mechanisms in Rat Brain

Tartrazine, an azo dye used in food, cosmetics, and pharmaceuticals with the effects on cell cycle, is not well understood. Therefore, we investigated the toxicity of tartrazine in rat brain with high-dose aspirin. Male Wistar rats (n = 24) were divided into (C) control, (T) tartrazine (700 mg/kg body weight [BW] at weeks 1 and 2), (A) aspirin (150 mg/kg [BW] at weeks 1, 2, and 3), and (TA) aspirin + tartrazine (150 mg/kg [BW] aspirin at weeks 1, 2, and 3 and 700 mg/kg [BW] tartrazine at weeks 1 and 2) groups. The expression of p53, B cell lymphoma-2 extra-large (Bcl-xL), cyclin-dependent kinase 2 (CDK2), p27, and Ki67 was evaluated by quantitative reverse-transcription PCR. A histopathological analysis of brain tissue and oxidative stress level was assessed based on reduced glutathione (GSH), ascorbic acid (AA), and malondialdehyde levels. We found that Bcl-xL, Ki67, CDK2, and p27 were upregulated and p53 was downregulated in the tartrazine-treated group as compared to the control group. Aspirin administration reversed these changes except P53 expression. Tartrazine had no effect on lipid peroxidation but altered AA and GSH levels with no reversal by aspirin treatment. Histopathological analysis revealed that aspirin prevented tartrazine-induced damage including increased perivascular space and hemorrhage. These results indicate that aspirin protects the brain from tartrazine-induced toxicity independent of p53 signaling and antioxidant mechanisms.

Probucol Protects Against Contrast-Induced Acute Kidney Injury via the Extracellular Signal-Regulated Kinases 1 and 2 (ERK1/2)/JNK-Caspase 3 Pathway in Diabetic Rats

Background

Contrast-induced acute kidney injury is an important clinical problem, yet its pathogenic mechanisms are incompletely understood. In this study we explored the potential beneficial effects of probucol as treatment of contrast-induced acute kidney injury in diabetic rats.

Material/Methods

Rats were divided into 3 groups: i) diabetic control, ii) diabetic with contrast, and iii) probucol treatment groups. Probucol was administered by gavage and the contrast diatrizoate (60%) was injected via femoral vein. After 24 h, the rats were sacrificed and samples were taken to measure biochemical indicators. Pathological damage of renal tubules was evaluated by HE staining. Expression of Bcl-2, Bax, p-ERKs, and p-JNK proteins in the kidneys was examined by Western blotting, whereas expression level of caspase-3 in kidneys was detected by immunohistochemistry.

Results

Compared to the probucol treatment group, the diabetes with contrast group showed higher serum creatinine and lower creatinine clearance. The pathological changes of kidneys in the probucol treatment group were improved compared with the contrast group. Moreover, Western blot analyses revealed that use of contrast agent led to lower p-ERK1/2, higher p-JNK, lower Bcl-2, and higher Bax levels, which were reversed by probucol. Finally, immunohistochemical findings revealed higher caspase-3 after contrast use, which was partially reversed by probucol.

Conclusions

Probucol exerts protective effects on contrast-induced acute kidney injury in diabetic rats by inhibition of renal cell apoptosis. This is achieved by reducing mitochondrial caspase-3 expression through increasing and decreasing the expression of the upstream mediators p-ERK1/2 and p-JNK, respectively.

Bcl-2 expression and prognostic significance in feline invasive mammary carcinomas: a retrospective observational study

BACKGROUND

Cats spontaneously develop invasive mammary carcinomas with high clinical aggressiveness, and are considered relevant animal models for human breast cancer. Bcl-2 is an anti-apoptotic pro-survival protein, whose expression is associated with a favorable outcome in human breast cancer. The aim of our study was to determine the frequency of Bcl-2 expression in feline invasive mammary carcinomas (FMCs), its relationship with other clinicopathologic variables, and its prognostic value. This retrospective study included 180 FMCs, diagnosed in female cats treated by surgery only, with a 2-year follow-up post-mastectomy. Bcl-2, ER, PR, Ki-67, HER2, and CK5/6 expression were determined by automated immunohistochemistry. A receiver-operating-characteristic curve was used to set the threshold for Bcl-2 positivity.

RESULTS

The cohort comprises 32% (57/180) luminal FMCs defined by ER and/or PR positivity, and 68% (123/180) triple-negative FMCs (negative for ER, PR, and HER2). Bcl-2 expression was considered as positive when at least 65% of tumor cells were immunohistochemically stained. Thirty-one out of 180 FMCs (17%) were Bcl-2-positive. There was no significant association between Bcl-2 expression, and the tumor size, nodal stage, histological grade, or ER, PR, Ki-67, HER2, and CK5/6 expression. By multivariate survival analysis (Cox proportional-hazards regression), Bcl-2 positivity in FMCs was associated with longer disease-free interval (p = 0.005, HR = 0.38), overall survival (p = 0.028, HR = 0.61), and cancer-specific survival (p = 0.019, HR = 0.54) independently of other powerful prognostic factors such as pathologic tumor size, pathologic nodal stage, and distant metastasis. The positive prognostic value of Bcl-2 was confirmed in both luminal FMCs, of which 9/57 (16%) were Bcl-2-positive, and in basal-like triple-negative (ER-, PR-, HER2-, CK5/6+) FMCs, of which 14/76 (18%) were Bcl-2-positive.

CONCLUSIONS

Compared to human breast cancer, Bcl-2 positivity in feline invasive mammary carcinomas is also associated with better outcome, but is less common, and not associated with ER, PR, and HER2 expression. Cats with spontaneous Bcl-2-positive FMCs could be useful in preclinical trials evaluating anti-Bcl-2 strategies for chemoresistant luminal or triple-negative breast cancers.

New Drugs from the Sea: Pro-Apoptotic Activity of Sponges and Algae Derived Compounds

Natural compounds derived from marine organisms exhibit a wide variety of biological activities. Over the last decades, a great interest has been focused on the anti-tumour role of sponges and algae that constitute the major source of these bioactive metabolites. A substantial number of chemically different structures from different species have demonstrated inhibition of tumour growth and progression by inducing apoptosis in several types of human cancer. The molecular mechanisms by which marine natural products activate apoptosis mainly include (1) a dysregulation of the mitochondrial pathway; (2) the activation of caspases; and/or (3) increase of death signals through transmembrane death receptors. This great variety of mechanisms of action may help to overcome the multitude of resistances exhibited by different tumour specimens. Therefore, products from marine organisms and their synthetic derivates might represent promising sources for new anticancer drugs, both as single agents or as co-adjuvants with other chemotherapeutics. This review will focus on some selected bioactive molecules from sponges and algae with pro-apoptotic potential in tumour cells.

miR‑15a‑3p affects the proliferation, migration and apoptosis of lens epithelial cells

The present study investigated the effect of microRNA (miR)-15a-3p on the proliferation, migration and apoptosis of lens epithelial cells and its potential mechanism, in order to further elucidate the pathogenesis of age-related cataracts (ARCs). The HLE-B3 human lens epithelial cell line was transfected with miR-15a-3p mimic. Expression of the miR-15a-3p mimic was measured by fluorescence-based reverse transcription-quantitative polymerase chain reaction analysis. Cell proliferation, apoptosis, invasion and migration were investigated using MTT and plate clone formation assays, terminal deoxynucleotidyl transferase dUTP nick end labeling and flow cytometry, and a wound healing assay and Transwell assay, respectively. The protein expression levels of B-cell lymphoma 2 (BCL2) and myeloid cell leukemia sequence 1 (MCL1) were also compared between transfected and wild-type HLE-B3 cells by western blot analysis. The results showed that transfection with the miR-15a-3p mimic significantly suppressed the proliferation of HLE-B3 cells, induced cell apoptosis and increased the proportion of early apoptotic cells. The migration of HLE-B3 cells was significantly inhibited following transfection with miR-15a-3p mimic (P<0.01), whereas cell invasion was unaffected (P>0.05). In addition, reduced protein levels of BCL2 and MCL1 were observed in the miR-15a-3p mimic-transfected HLE-B3 cells (P<0.01). In conclusion, miR-15a-3p may suppress cell proliferation and migration, and induce cell apoptosis in lens epithelial cells through inhibiting the expression of BCL2 and MCL1, which contributes to the onset of ARCs.

Bcl-2 Inhibition to Overcome Resistance to Chemo- and Immunotherapy

Abstract: According to the World Health Organization (WHO), cancer is a leading cause of death worldwide. The identification of novel targets for cancer treatment is an area of intense work that has led Bcl-2 over-expression to be proposed as one of the hallmarks of cancer and Bcl-2 inhibition as a promising strategy for cancer treatment. In this review, we describe the different pathways related to programmed cell death, the role of Bcl-2 family members in apoptosis resistance to anti-cancer treatments, and the potential utility of Bcl-2 inhibitors to overcome resistance to chemo- and immunotherapy.

Bcl-2 Family Overexpression and Chemoresistance in Acute Myeloid Leukemia

The family of Bcl-2 proteins is one of the most responsible for apoptosis pathway, that is a critical process to the maintenance of tissue homeostasis. Bcl-2 is an essential apoptotic regulator belonging to a family of functionally and structurally related proteins known as the Bcl-2 family. Some members of this family act as anti-apoptotic regulators, whereas others act in pro-apoptotic function. The relationship between the pro and anti-apoptotic proteins can regulate whether cells begin the apoptosis or remain its life cycle. Increasing of Bcl-2 expression has been found in some hematologic diseases, such as Acute Myeloid Leukemia (AML) and their effects on responsiveness to anticancer therapy have been recently described. Thus, this review aims to discuss apoptosis and the role of the Bcl-2 family of proteins in chemoresistance when overexpressed in patients committed with Acute Myeloid Leukemia submitted to chemotherapy treatment.

The role of GLI-SOX2 signaling axis for gemcitabine resistance in pancreatic cancer

Pancreatic cancer, mostly pancreatic ductal adenocarcinomas (PDAC), is one of the most lethal cancers, with a dismal median survival around 8 months. PDAC is notoriously resistant to chemotherapy. Thus far, numerous attempts using novel targeted therapies and immunotherapies yielded limited clinical benefits for pancreatic cancer patients. It is hoped that delineating the molecular mechanisms underlying drug resistance in pancreatic cancer may provide novel therapeutic options. Using acquired gemcitabine resistant pancreatic cell lines, we revealed an important role of the GLI-SOX2 signaling axis for regulation of gemcitabine sensitivity in vitro and in animal models. Down-regulation of GLI transcriptional factors (GLI1 or GLI2), but not SMO signaling inhibition, reduces tumor sphere formation, a characteristics of tumor initiating cell (TIC). Down-regulation of GLI transcription factors also decreased expression of TIC marker CD24. Similarly, high SOX2 expression is associated with gemcitabine resistance whereas down-regulation of SOX2 sensitizes pancreatic cancer cells to gemcitabine treatment. We further revealed that elevated SOX2 expression is associated with an increase in GLI1 or GLI2 expression. Our ChIP assay revealed that GLI proteins are associated with a putative Gli binding site within the SOX2 promoter, suggesting a more direct regulation of SOX2 by GLI transcription factors. The relevance of our findings to human disease was revealed in human cancer specimens. We found that high SOX2 protein expression is associated with frequent tumor relapse and poor survival in stage II PDAC patients (all of them underwent gemcitabine treatment), indicating that reduced SOX2 expression or down-regulation of GLI transcription factors may be effective in sensitizing pancreatic cancer cells to gemcitabine treatment.

Loss of p53 suppresses replication-stress-induced DNA breakage in G1/S checkpoint deficient cells

In cancer cells, loss of G1/S control is often accompanied by p53 pathway inactivation, the latter usually rationalized as a necessity for suppressing cell cycle arrest and apoptosis. However, we found an unanticipated effect of p53 loss in mouse and human G1-checkpoint-deficient cells: reduction of DNA damage. We show that abrogation of the G1/S-checkpoint allowed cells to enter S-phase under growth-restricting conditions at the expense of severe replication stress manifesting as decelerated DNA replication, reduced origin firing and accumulation of DNA double-strand breaks. In this system, loss of p53 allowed mitogen-independent proliferation, not by suppressing apoptosis, but rather by restoring origin firing and reducing DNA breakage. Loss of G1/S control also caused DNA damage and activation of p53 in an in vivo retinoblastoma model. Moreover, in a teratoma model, loss of p53 reduced DNA breakage. Thus, loss of p53 may promote growth of incipient cancer cells by reducing replication-stress-induced DNA damage.

Targeting proteasome-associated deubiquitinases as a novel strategy for the treatment of estrogen receptor-positive breast cancer

Estrogen receptor α (ERα) is expressed in ~67% of breast cancers and is critical to their proliferation and progression. The expression of ERα is regarded as a major prognostic marker, making it a meaningful target to treat breast cancer (BCa). However, hormone receptor-positive BCa was sometimes irresponsive or even resistant to classic anti-hormonal therapies (e.g., fulvestrant and tamoxifen). Hence, novel anti-endocrine therapies are urgent for ERα⁺ BCa. A phase II study suggested that bortezomib, an inhibitor blocking the activity of 20 S proteasomes, intervenes in cancer progression for anti-endocrine therapy in BCa. Here we report that proteasome-associated deubiquitinases (USP14 and UCHL5) inhibitors b-AP15 and platinum pyrithione (PtPT) induce growth inhibition in ERα⁺ BCa cells. Further studies show that these inhibitors induce cell cycle arrest and apoptosis associated with caspase activation, endoplasmic reticulum (ER) stress and the downregulation of ERα. Moreover, we suggest that b-AP15 and PtPT block ERα signaling via enhancing the ubiquitin-mediated degradation of ERα and inhibiting the transcription of ERα. Collectively, these findings demonstrate that proteasome-associated deubiquitinases inhibitors b-AP15 and PtPT may have the potential to treat BCa resistant to anti-hormonal therapy.

Butein induces apoptotic cell death of human cervical cancer cells

Butein is a chalcone, a flavonoid that is widely biosynthesized in plants. Butein has been identified to possess varied pharmacological activity and is extractable from traditional Chinese medicinal herbs, therefore applicable for disease treatment. Recently, in vitro and in vivo studies have shown that butein may induce apoptotic cell death in various human cancer cells. In this study we investigated the apoptotic effect of butein and the underlying mechanisms in human cervical cancer cells. Two cell lines, C-33A and SiHa cells, were treated with butein at different dosages for different durations. The effect of butein on cell viability was assessed by MTT assay, which revealed that butein exerted cytotoxicity in both cervical cancer cells in a dose- and time-dependent fashion. Apoptotic pathway-related factors in the butein-treated cervical cancer cells were then examined. JC-1 flow cytometry, cytochrome c assay, and caspase activity assays demonstrated that butein disturbed mitochondrial transmembrane potential, and increased cytosolic cytochrome c levels and caspase activities in both cervical cancer cells. Western blot analysis revealed that butein downregulated anti-apoptotic protein Bcl-xL and led to proteolytic cleavage of poly (ADP-ribose) polymerase. In addition, butein decreased expressions of the inhibitor of apoptosis (IAP) proteins, including X-linked IAP, survivin, and cellular IAP-1. The findings of this study suggest that butein can decrease cervical cancer cell viability via a pro-apoptotic effect, which involves inhibition of the IAP proteins and activation of both extrinsic and intrinsic pro-apoptotic pathways. Therefore, butein may be applicable for cervical cancer treatment.

Re-inforcing the cell death army in the fight against breast cancer

Metastatic breast cancer is responsible for most breast cancer-related deaths. Disseminated cancer cells have developed an intrinsic ability to resist anchorage-dependent apoptosis (anoikis). Anoikis is caused by the absence of cellular adhesion, a process that underpins lumen formation and maintenance during mammary gland development and homeostasis. In healthy cells, anoikis is mostly governed by B-cell lymphoma-2 (BCL2) protein family members. Metastatic cancer cells, however, have often developed autocrine BCL2-dependent resistance mechanisms to counteract anoikis. In this Review, we discuss how a pro-apoptotic subgroup of the BCL2 protein family, known as the BH3-only proteins, controls apoptosis and anoikis during mammary gland homeostasis and to what extent their inhibition confers tumor suppressive functions in metastatic breast cancer. Specifically, the role of the two pro-apoptotic BH3-only proteins BCL2-modifying factor (BMF) and BCL2-interacting mediator of cell death (BIM) will be discussed here. We assess current developments in treatment that focus on mimicking the function of the BH3-only proteins to induce apoptosis, and consider their applicability to restore normal apoptotic responses in anchorage-independent disseminating tumor cells.

MiR-335-5p restores cisplatin sensitivity in ovarian cancer cells through targeting BCL2L2

Objective

Our study was designed to explore the association miR‐335‐5p and BCL2L2 and to investigate the influence of miR‐335‐5p/BCL2L2 axis on cisplatin‐resistant ovarian cancer cells.

Methods

Microarray analysis was used to determine differentially expressed microRNAs in primary and cisplatin‐resistant A2780 cells. Cell function experiments were conducted to investigate the effect of miR‐335‐5p on the cisplatin sensitivity of A2780 cells. The targeted relationship between BCL2L2 mRNA and miR‐335‐5p was validated through luciferase assay. Tumor xenograft was performed to confirm the function of miR‐335‐5p in restoring the cisplatin sensitivity of the ovarian cancer cells.

Results

MiR‐335‐5p was lowly expressed in cisplatin‐resistant A2780 cells. Overexpression of miR‐335‐5p reduced cell survival and enhanced cisplatin‐induced cell apoptosis. BCL2L2 mRNA was a target of miR‐335‐5p, and silencing of BCL2L2 showed the similar results on the cell viability as miR‐335‐5p overexpression.

Conclusion

Upregulation of miR‐335‐5p expression enhanced the cisplatin sensitivity of ovarian cancer cells through suppressing BCL2L2, suggesting the potential of miR‐335‐5p/BCL2L2 axis as a therapeutic target for the cisplatin resistance of patients with ovarian cancer.

Apoptosis: Activation and Inhibition in Health and Disease

There are many types of cell death, each involving multiple and complex molecular events. Cell death can occur accidentally when exposed to extreme physical, chemical, or mechanical conditions, or it can also be regulated, which involves a genetically coded complex machinery to carry out the process. Apoptosis is an example of the latter. Apoptotic cell death can be triggered through different intracellular signalling pathways that lead to morphological changes and eventually cell death. This is a normal and biological process carried out during maturation, remodelling, growth, and development in tissues. To maintain tissue homeostasis, regulatory, and inhibitory mechanisms must control apoptosis. Paradoxically, these same pathways are utilized during infection by distinct intracellular microorganisms to evade recognition by the immune system and therefore survive, reproduce and develop. In cancer, neoplastic cells inhibit apoptosis, thus allowing their survival and increasing their capability to invade different tissues and organs. The purpose of this work is to review the generalities of the molecular mechanisms and signalling pathways involved in apoptosis induction and inhibition. Additionally, we compile the current evidence of apoptosis modulation during cancer and Leishmania infection as a model of apoptosis regulation by an intracellular microorganism.

Decoction of Chinese Herbal Medicine Fuzheng Kang-Ai Induces Lung Cancer Cell Apoptosis via STAT3/Bcl-2/Caspase-3 Pathway

Decoction of Chinese herbal medicine (CHM) Fuzheng Kang-Ai (FZKA for short) has been applied as adjuvant treatment strategy in advanced lung cancer patients for decades. We previously showed that FZKA decoction inhibited proliferation of non-small cell lung cancer (NSCLC) cells through activation of AMP-activated protein kinase alpha (AMPKα) signaling pathway, followed by inducing insulin-like growth factor (IGF) binding protein 1 (IGFBP1) and forkhead homeobox type O3a (FOXO3a) proteins, and enhanced the inhibition effect of gefitinib in lung cancer cell growth via inactivating PI3-K/Akt-mediated suppressing of cell surface-associated mucin-1 (MUC1) expression. In this study, we investigated the molecular mechanism by which FZKA decoction affected cell apoptosis in lung cancer cells. Our results show that FZKA induced apoptosis in lung cancer cells. Mechanistically, FZKA activated the caspase-3, PARP, and caspase-9 activities. Both antiapoptotic and proapoptotic proteins from Bcl-2 family were deregulated by FZKA exposure in lung cancer cells. In addition, FZKA reduced protein expressions of signal transducer and activator of transcription 3 (STAT3) and Jun activation domain-binding protein 1 (Jab1), while it concomitantly increased p21 protein. Moreover, the inhibitor of caspase-3 resisted the effect of FZKA on induction of apoptosis. Finally, exogenous overexpression of STAT3 overcame FZKA-inhibited protein expressions of Bcl-2 and myeloid cell leukemia-1 (Mcl-1) as well as Bax and blocked FZKA-induced activities of caspase-3 and caspase-9. Our results show that FZKA decoction promotes lung cancer cell apoptosis through STAT3/Bcl-2/caspase-3 signaling pathways. This study unveils potential novel molecular mechanism by which FZKA controls growth of human lung cancer cells.

MicroRNA-365 Inhibits Cell Growth and Promotes Apoptosis in Melanoma by Targeting BCL2 and Cyclin D1 (CCND1)

BACKGROUND MicroRNA-365 (miR-365) is involved in the development of a variety of cancers. However, it remains largely unknown if and how miRNAs-365 plays a role in melanoma development. MATERIAL AND METHODS In this study, we overexpressed miR-365 in melanoma cell lines A375 and A2058, via transfection of miR-365 mimics oligos. We then investigated alterations in a series of cancer-related phenotypes, including cell viability, cell cycle, apoptosis, colony formation, and migration and invasion capacities. We also validated cyclin D1 (CCND1) and BCL2 apoptosis regulator (BCL2) as direct target genes of miR-365 by luciferase reporter assay and investigated their roles in miR-365 caused phenotypic changes. To get a more general view of miR-365's biological functions, candidate target genes of miR-365 were retrieved via searching online databases, which were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses for potential biological functions. We then analyzed The Cancer Genome Atlas (TCGA) Skin Cutaneous Melanoma (SKCM) dataset for correlation between miR-365 level and clinicopathological features of patients, and for survival of patients with high and low miR-365 levels. RESULTS We found that miR-365 was downregulated in melanoma cells. Overexpression of miR-365 remarkably suppressed cell proliferation, induced cell cycle arrest and apoptosis, and compromised the migration and invasion capacities in A375 and A2058 cell lines. We also found that the phenotypic alterations by miR-365 were partially due to downregulation of CCND1 and BCL2 oncogenes. The bioinformatics analysis revealed that predicted targets of miR-365 were widely involved in transcriptional regulation and cancer-related signaling pathways. However, analysis of SKCM dataset failed to find differences in miR-365 level among melanoma patients at different clinicopathologic stages. The Kaplan-Meier analysis also failed to discover significant differences in overall survival and disease-free survival between patients with high and low miR-365 levels. CONCLUSIONS Our findings suggested that miR-365 might be an important novel regulator for melanoma formation and development, however, the in vivo roles in melanoma developments need further investigation.

Pro-apoptotic Bax promotes mesenchymal-epithelial transition by binding to respiratory complex-I and antagonizing the malignant actions of pro-survival Bcl-2 proteins

The plasticity of solid tumors between the epithelial and mesenchymal states critically influences their malignant progression and metastasis. The epithelial-mesenchymal transition (EMT), which supports cancer cell invasion and metastasis, is promoted by pro-survival members (e.g., Bcl-2 and Bcl-X_L) of the Bcl-2 protein family, which are well-known key apoptosis regulators. We found that Bcl-w, another pro-survival member, promotes EMT by increasing respiratory complex-I activity and reactive oxygen species (ROS) levels. In contrast, pro-apoptotic Bax facilitates mesenchymal-epithelial transition by binding to complex-I, which inhibits complex-I-induced ROS production. Functional antagonism between pro-survival and pro-apoptotic proteins in regulating tumor plasticity was directly confirmed by co-expressing Bax with Bcl-w or Bcl-X_L. Therefore, the balance between the functionally opposing Bcl-2 proteins appears to be a critical determinant of cancer cell phenotypes. We further showed that sub-lethal doses of γ-radiation induced EMT by increasing Bcl-X_L and Bcl-w levels and complex-I activity. We propose that Bcl-2 proteins and complex-I are potential targets for preventing tumor progression and the malignant actions of radiotherapy.

Molecular mechanisms involving prostate cancer racial disparity

Prostate cancer (PCa) is the second leading cause of cancer-related deaths in the United States. The African (AA) descent has greater incidence and mortality rates of PCa as compared to Caucasian (CA) men. While socioeconomic differences across racial groups contribute to disparity in PCa, increasing evidence points that genetic and molecular alterations play important roles in racial disparities associated with PCa. In this review, we focus on genetic and molecular influences that contribute to racial disparity between AA and CA men including: androgen and estrogen receptor signaling pathways, growth factors, apoptotic proteins, genetic, genomic and epigenetic alterations. Future translational studies will identify prognostic and predictive biomarkers for AA PCa and assist in the development of new targeted-therapies specifically for AA men with PCa.

PTD4-apoptin induces Bcl-2-insensitive apoptosis in human cervical carcinoma in vitro and in vivo

Worldwide, cervix carcinoma is among the most dangerous cancer types, and novel therapies are under development. Cancer treatments are often hampered because of lack of specificity. The chicken anemia virus-derived apoptin induces apoptosis selectively in tumor cells and leaves normal cells unharmed. Here, we have carried out in-vitro and in-vivo studies on the cytotoxic effect of apoptin in a cervix carcinoma model. Apoptin was fused to the protein transduction domain 4 (PTD4), enabling delivery of the fusion protein across cellular membranes. PTD4-apoptin protein is located in the nuclei of human cervical carcinoma HeLa cells and in the cytoplasm of normal cells L02. By MTT and flow cytometry analysis, we have proven that PTD4-apoptin protein induced apoptosis in the cervical carcinoma cells. PTD4-apoptin enhanced the level of active executioner caspase-3. Neither caspase-3 activation nor apoptin-induced accumulation of the mitochondrial outer-membrane protein Mfn-2 was affected by ectopic Bcl-2 expression. In contrast, apoptin-mediated AKT activation was inhibited by Bcl-2. In vivo, cervix carcinoma xenografts were treated for 7 days with PTD4-apoptin protein. The PTD4-apoptin treatment induced a decrease in the cervix carcinoma, whereas the PTD4-GFP protein-treated controls expanded significantly. TUNEL analysis showed that PTD4-apoptin protein induced apoptosis in cervix carcinoma cells, in contrast to the control PTD-GFP-treated ones. Our results indicate that apoptin is a potential anticancer agent for treating cervix carcinoma.

Emerging roles of hnRNPA1 in modulating malignant transformation

Heterogeneous nuclear ribonucleoproteins (hnRNPs) are RNA-binding proteins associated with complex and diverse biological processes such as processing of heterogeneous nuclear RNAs (hnRNAs) into mature mRNAs, RNA splicing, transactivation of gene expression, and modulation of protein translation. hnRNPA1 is the most abundant and ubiquitously expressed member of this protein family and has been shown to be involved in multiple molecular events driving malignant transformation. In addition to selective mRNA splicing events promoting expression of specific protein variants, hnRNPA1 regulates the gene expression and translation of several key players associated with tumorigenesis and cancer progression. Here, we will summarize our current knowledge of the involvement of hnRNPA1 in cancer, including its roles in regulating cell proliferation, invasiveness, metabolism, adaptation to stress and immortalization. WIREs RNA 2017, 8:e1431. doi: 10.1002/wrna.1431 For further resources related to this article, please visit the WIREs website.

Isoalantolactone induces intrinsic apoptosis through p53 signaling pathway in human lung squamous carcinoma cells

Isoalantolactone has recently been revealed to induce apoptosis in several types of cancer. However, little is reported on its anti-tumor potential on human lung cancer. Our present study was designed to investigate its effects on human lung squamous carcinoma SK-MES-1 cells. We found that Isoalantolactone induced cellular and DNA morphological changes and decreased the viability of SK-MES-1 cells. It significantly inhibited the growth of SK-MES-1 cells through apoptosis in a dose-dependent manner via activation of p53. It also induced cell cycle arrest at G1 phase. It can down-regulate Bcl-2 and up-regulate Bax, to induce dissipation of mitochondrial membrane potential and generation of reactive oxygen species. Caspase-3 was also activated by Isoalantolactone, with the cleavage of poly (ADP-ribose) polymerase. Our results reveal that Isoalantolactone induces intrinsic apoptosis in SK-MES-1 cells through p53 signaling pathway, which suggests that Isoalantolactone could be a potential leading compound for future development of anti-lung cancer drugs.

A novel deubiquitinase inhibitor b-AP15 triggers apoptosis in both androgen receptor-dependent and -independent prostate cancers

Prostate cancer (PCa) remains a leading cause of cancer-related death in men. Especially, a subset of patients will eventually progress to the metastatic castrate-resistant prostate cancer (CRPC) which is currently incurable. Deubiquitinases (DUBs) associated with the 19S proteasome regulatory particle are increasingly emerging as significant therapeutic targets in numerous cancers. Recently, a novel small molecule b-AP15 is identified as an inhibitor of the USP14/UCHL5 (DUBs) of the 19S proteasome, resulting in cell growth inhibition and apoptosis in several human cancer cell lines. Here, we studied the therapeutic effect of b-AP15 in PCa, and our results indicate that (i) b-AP15 decreases viability, proliferation and triggers cytotoxicity to both androgen receptor-dependent and -independent PCa cells in vitro and in vivo, associated with caspase activation, inhibition of mitochondria function, increased reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress; (ii) pan-caspase inhibitor z-VAD-FMK and ROS scavenger N-acetyl-L-cysteine (NAC) efficiently block apoptosis but not proteasome inhibition induced by exposure of b-AP15; (iii) treatment with b-AP15 in androgen-dependent prostate cancer (ADPC) cells down-regulates the expression of androgen receptor (AR), which is degraded via the ubiquitin proteasome system. Hence, the potent anti-tumor effect of b-AP15 on both androgen receptor-dependent and -independent PCa cells identifies a new promising therapeutic strategy for prostate cancer.

Bcl-2 degradation is an additional pro-apoptotic effect of polo-like kinase inhibition in cholangiocarcinoma cells

AIM

To examine the influence on apoptotic mechanisms following inhibition of polo-like kinases as therapeutically approach for cholangiocellular cancer treatment.

METHODS

As most cholangiocarcinomas are chemotherapy-resistant due to mechanisms preventing tumor cell death, we investigated the effect of Cisplatin on cholangiocellular carcinoma (CCA) cell lines KMCH-1 and Mz-Ch-1. Polo-like kinases (PLK) are important regulators of the cell cycle and their inhibition is discussed as a potential therapy while PLK inhibition can regulate apoptotic mediators. Here, cells were treated with PLK inhibitor BI6727 (Volasertib), Cisplatin, and in combination of both compounds. Cell viability was assessed by MTT; apoptosis was measured by DAPI staining and caspase-3/-7 assay. Western blot and qRT-PCR were used to measure expression levels of apoptosis-related molecules Bax and Bcl-2.

RESULTS

The cell viability in the CCA cell lines KMCH-1 and Mz-Ch-1 was reduced in all treatment conditions compared to vehicle-treated cells. Co-treatment with BI6727 and cisplatin could even enhance the cytotoxic effect of cisplatin single treatment. Thus, co-treatment of cisplatin with BI6727 could slightly enhance the cytotoxic effect of the cisplatin in both cell lines whereas there was evidence of increased apoptosis induction solely in Mz-Ch-1 as compared to KMCH-1. Moreover, PLK inhibition decreases protein levels of Bcl-2; an effect that can be reversed by the proteasomal degradation inhibitor MG-132. In contrast, protein levels of Bax were not found to be altered by PLK inhibition. These findings indicate that cytotoxic effects of Cisplatin in Mz-Ch-1 cells can be enhanced by cotreatment with BI6727.

CONCLUSION

In conclusion, BI6727 treatment can sensitize CCA cells to cisplatin-induced apoptosis with proteasomal Bcl-2 degradation as an additional pro-apoptotic effect.

APOPTOSIS INDUCTION OF EPIFRIEDELINOL ON HUMAN CERVICAL CANCER CELL LINE

Background:

Present investigation evaluates the antitumor activity of epifriedelinol for the management of cervical cancer by inducing process of apoptosis.

Methods:

Human Cervical Cancer Cell Line, C33A and HeLa were selected for study and treated with epifriedelinol at a concentration of (50-1000 µg/ml). Cytotoxicity of epifriedelinol was estimated by MTT assay and induction of apoptosis was assessed by estimating the activity of caspase 3, 8 and 9 enzyme, apoptosis assay and translocation of cytochrome c. Moreover an expression of several proteins that plays role in the apoptosis process was estimated by western blot method.

Results:

Result of the study suggested that treatment with epifriedelinol significantly decrease the viability count of cancerous cell in a dose perndent manner and also enhances the formation of oligonucleosome in both the cell lines. However activity of caspase enzymes and translocation of cytochrome c were enhanced after treatment with epifriedelinol. It was also observed that epifriedelinol treatment alters the ratio of pro-apoptotic to anti-apoptotic proteins and enhances the expressions of inhibitor of apoptosis proteins (IAP).

Conclusion:

Result of our study proves the anticancer activity of epifriedelinol in cervical cancer by inducing apoptosis as treatment with it enhances the production of oligonucleosomes, translocation of cytochrome c and activity caspase enzymes.

Autocrine Prolactin Stimulates Endometrial Carcinoma Growth and Metastasis and Reduces Sensitivity to Chemotherapy

Advanced and recurrent endometrial carcinoma (EC) exhibits a poor response to chemotherapy and low survival rates. It has been previously reported that human prolactin (hPRL) is upregulated in endometrial cancer and is associated with worse survival outcomes. We provide evidence for the functional role of hPRL in EC progression. We generated a model for the study of autocrine hPRL-mediated cell functional effects through the forced expression of hPRL in human EC cells. Autocrine hPRL expression stimulated cell proliferation, anchorage-independent growth, migration, and invasion of EC cells and promoted tumor growth, local invasion, and metastatic colonization in xenograft models. In addition, forced expression of hPRL decreased sensitivity of EC cells to chemotherapeutic drugs (i.e., doxorubicin and paclitaxel), both in vitro and in vivo. Consistently, small interfering RNA-mediated depletion of hPRL significantly reduced oncogenicity and enhanced the chemosensitivity of EC cells. As CD24 is hPRL-regulated and has been implicated in drug resistance in EC, we further showed that CD24 is a critical mediator of hPRL-stimulated reduced sensitivity to doxorubicin and paclitaxel in EC cells. Therefore, inhibition of hPRL signaling is a potential therapeutic strategy for the treatment of late-stage EC, which can be used in combination with chemotherapy to improve the chemotherapeutic response.

BCLB, methylated in hepatocellular carcinoma, is a starvation stress sensor that induces apoptosis and autophagy through the AMPK-mTOR signaling cascade

Epigenetic disruption of tumor suppressor genes (TSGs), particularly DNA methylation, plays a key role in hepatocellular carcinoma (HCC) pathogenesis. Through methylome study, we identified BCLB as a methylated gene in HCC. BCLB was methylated in all tumor cell lines with silenced or reduced expression. BCLB was further found to be silenced in 55.2% (58/105) of HCC samples, while 91.4% (96/105) of paired non-tumor tissues showed high BCLB expression. BCLB protein expression was significantly correlated with HBV status (p = 0.036), AFP (p = 0.048), tumor size (p = 0.006), and TNM stage (p = 0.022). The overall survival and disease-free survival rate of HCC patients with positive BCLB expression were both significantly higher than those with negative BCLB expression (p = 0.032 and 0.027, respectively). Ectopic expression of BCLB in HCC cells inhibited cell growth in vitro and in vivo. Mechanistic study showed that BCLB expression was a starvation stress sensor inducing apoptosis and autophagy simultaneously in HCC cells through the adenosine monophosphate-activated protein kinase AMPK-mTOR signaling cascade. Thus, epigenetic suppression of BCLB expression is involved in HCC development, which might have therapeutic implications for HCC patients.

Anti-Metastatic Effect of Dehydrocorydaline on H1299 Non-Small Cell Lung Carcinoma Cells via Inhibition of Matrix Metalloproteinases and B Cell Lymphoma 2

Though Dehydrocorydaline, an alkaloid isolated from Corydalis turtschaninovii tuber, was known to have anti-coronary artery disease, anti-inflammatory, apoptotic, anti-allergic, anti-acetylcholinesterase, and antitumor effects, the underlying anti-metastatic mechanism of Dehydrocorydalin was never elucidated in lung cancer cells so far. Thus, in the present study, the anti-metastatic effect of Dehydrocorydaline was examined in non-small cell lung carcinoma (NSCLC) cells, mainly targeting matrix metalloproteinases (MMPs) and B cell lymphoma-2 (Bcl-2) signaling. Here, Dehydrocorydaline exerted weak cytotoxicity and attenuated the protein expression of Bcl-2 and activated Bax in a concentration-dependent manner in NSCLC cells, such as A549, H460, H1299, and H596 cells. Also, Dehydrocorydaline suppressed the migration of H1299 cells by wound healing assay and transwell migration assay. Consistently, Dehydrocorydaline attenuated mRNA and protein levels of MMP7 and MMP9 as metastasis biomarkers in H1299 cells by quantitative reverse transcription polymerase chain reaction. Of note, Bcl-2 overexpression reduced the cytotoxic and anti-metastatic effects of Dehydrocorydaline on pCDNA-Bcl-2 transfected H1299 cells. Overall, our findings provide scientific evidence that Dehydrocorydaline exerts anti-metastatic potential via suppression of MMPs and Bcl-2 signaling in NSCLC cells. Copyright © 2017 John Wiley & Sons, Ltd.

ApoptomiRs of Breast Cancer: Basics to Clinics

Apoptosis, a form of programmed cell death, is a highly regulated process, the deregulation of which has been associated with the tumor initiation, progression, and metastasis in various cancers including breast cancer. Induction of apoptosis is a popular target of various therapies currently being tested or used for breast cancer treatment. Thus, identifying apoptotic mediators and regulators is imperative for molecular biologists and clinicians for benefit of patients. The regulation of apoptosis is complex and involves a tight equilibrium between the pro- and anti-apoptotic factors. Recent studies have highlighted the role of miRNAs in the control of apoptosis and their interplay with p53, the master guardian of apoptosis. Here, we summarize and integrate the data on the role of miRNAs in apoptosis in breast cancer and the clinical advantage it may offer for the prognosis or treatment of breast cancer patients.

Ligand-based chemoinformatic discovery of a novel small molecule inhibitor targeting CDC25 dual specificity phosphatases and displaying in vitro efficacy against melanoma cells

CDC25 phosphatases are important regulators of the cell cycle and represent promising targets for anticancer drug discovery. We recently identified NSC 119915 as a new quinonoid CDC25 inhibitor with potent anticancer activity. In order to discover more active analogs of NSC 119915, we performed a range of ligand-based chemoinformatic methods against the full ZINC drug-like subset and the NCI lead-like set. Nine compounds (3, 5-9, 21, 24, and 25) were identified with Ki values for CDC25A, -B and -C ranging from 0.01 to 4.4 μM. One of these analogs, 7, showed a high antiproliferative effect on human melanoma cell lines, A2058 and SAN. Compound 7 arrested melanoma cells in G2/M, causing a reduction of the protein levels of CDC25A and, more consistently, of CDC25C. Furthermore, an intrinsic apoptotic pathway was induced, which was mediated by ROS, because it was reverted in the presence of antioxidant N-acetyl-cysteine (NAC). Finally, 7 decreased the protein levels of phosphorylated Akt and increased those of p53, thus contributing to the regulation of chemosensitivity through the control of downstream Akt pathways in melanoma cells. Taken together, our data emphasize that CDC25 could be considered as a possible oncotarget in melanoma cells and that compound 7 is a small molecule CDC25 inhibitor that merits to be further evaluated as a chemotherapeutic agent for melanoma, likely in combination with other therapeutic compounds.

Triptolide exerts pro-apoptotic and cell cycle arrest activity on drug-resistant human lung cancer A549/Taxol cells via modulation of MAPK and PI3K/Akt signaling pathways

Multidrug resistance (MDR) is a major obstacle in the effective chemotherapeutic treatment of cancers. Triptolide (TPL) is a diterpenoid isolated from Tripterygium wilfordii Hook. f., a traditional Chinese medicine. It was demonstrated in our previous study that TPL exerts anti-MDR cancers on various MDR cell lines (including A549/Taxol, MCF-7/ADR and Bel7402/5-Fu). The present study was designed to investigate its anti-proliferative activity on A549/Taxol cells, and explore the underlying mechanism of action. The anti-proliferative activity of TPL on A549/Taxol cells was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Its pro-apoptosis and cell cycle arrest activities were analyzed by flow cytometry. Western blot assay was employed to investigate the levels of mitogen-activated protein kinases (MAPKs) and apoptosis-related proteins in cells. TPL efficiently suppressed the proliferation of A549/Taxol cells. Co-treatment with MAPK inhibitors in the MTT assay indicated that the extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) pathways were involved in the process. Upregulation of p-p38, p-ERK, p-GSK-3β, Bax and cleaved caspases-3 and -9, and downregulation of p-JNK, p-Akt and Bcl-2 were observed upon treatment with TPL in the A549/Taxol cells. The results from flow cytometry assay revealed that TPL induced apoptosis and S-phase arrest in A549/Taxol cells. This occurred as a result of the upregulation of p-ERK and p-GSK-3β, and the downregulation of p-JNK and p-Akt, and was responsible for the subsequent anti-proliferative activity.

Crocin treatment prevents doxorubicin-induced cardiotoxicity in rats

Doxorubicin (DOX)-induced cardiotoxicity is well-known as a serious complication of chemotherapy in patients with cancer. It is unknown whether crocin (CRO), main component of Crocus sativus L. (Saffron), could reduce the severity of DOX-induced cardiotoxicity. Therefore, this study was undertaken to assess the protective impact of CRO on DOX-induced cardiotoxicity in rats. The rats were divided into four groups: control, DOX (2mg/kg/48h, for 12days), and CRO groups that receiving DOX as in group 2 and CRO (20 and 40mg/kg/24h, for 20days) starting 4days prior to first DOX injection and throughout the study. Echocardiographic, electrocardiographic and hemodynamic studies, along with histopathological examination and MTT test were carried out. Our findings demonstrate that DOX resulted in cardiotoxicity manifested by decreased the left ventricular (LV) systolic and diastolic pressures, rate of rise/drop of LV pressure, ejection fraction, fractional shortening and contractility index, as compared to control group. In addition, histopathological analysis of heart confirmed adverse structural changes in myocardial cells following DOX administration. The results also showed that CRO treatment significantly improved DOX-induced heart damage, structural changes in the myocardium and ventricular function. In addition, CRO did not affect the in vitro antitumor activity of DOX. Taken together, our data confirm that CRO is protective against cardiovascular-related disorders produced by DOX, and clinical studies are needed to examine these findings in human.

Anti-proliferative and Apoptotic Effects of Dendrosomal Farnesiferol C on Gastric Cancer Cells

Farnesiferol C is a natural compound with various anti-cancer properties that belongs to the class of sesquiterpene coumarins. However, the low bioavailability of farnesiferol C limits its therapeutic potential. Here, we overcame this problem utilizing dendrosome nano-particles and evaluated the anti-cancer effect of dendrosomal farnesiferol C (DFC) on the AGS gastric cancer cell line. The 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and reverse transcriptase-polymerase chain reaction (RT-PCR) were respectively used to detect the anti-proliferative properties of DFC and expression ratio of Bax/Bcl-2 as a hallmark of apoptosis. Compared to the void farnesiferol C (FC), our data showed that DFC significantly suppresses the proliferation of AGS cells in a time- and dose-dependent manner (P<0.01). Also, DFC meaningfully increased the expression ratio of Bax/Bcl-2 in AGS cells (P<0.01). The findings demonstrate that our nano-based formulation of farnesiferol C could be considered as a potential therapeutic agent in cancer targeting.

In vitro short-term exposure to air pollution PM2.5-0.3 induced cell cycle alterations and genetic instability in a human lung cell coculture model

Although its adverse health effects of air pollution particulate matter (PM2.5) are well-documented and often related to oxidative stress and pro-inflammatory response, recent evidence support the role of the remodeling of the airway epithelium involving the regulation of cell death processes. Hence, the overarching goals of the present study were to use an in vitro coculture model, based on human AM and L132 cells to study the possible alteration of TP53-RB gene signaling pathways (i.e. cell cycle phases, gene expression of TP53, BCL2, BAX, P21, CCND1, and RB, and protein concentrations of their active forms), and genetic instability (i.e. LOH and/or MSI) in the PM2.5-0.3-exposed coculture model. PM2.5-0.3 exposure of human AM from the coculture model induced marked cell cycle alterations after 24h, as shown by increased numbers of L132 cells in subG1 and S+G2 cell cycle phases, indicating apoptosis and proliferation. Accordingly, activation of the TP53-RB gene signaling pathways after the coculture model exposure to PM2.5-0.3 was reported in the L132 cells. Exposure of human AM from the coculture model to PM2.5-0.3 resulted in MS alterations in 3p chromosome multiple critical regions in L132 cell population. Hence, in vitro short-term exposure of the coculture model to PM2.5-0.3 induced cell cycle alterations relying on the sequential occurrence of molecular abnormalities from TP53-RB gene signaling pathway activation and genetic instability.

HSP27 Inhibits Homocysteine-Induced Endothelial Apoptosis by Modulation of ROS Production and Mitochondrial Caspase-Dependent Apoptotic Pathway

Objectives. Elevated plasma homocysteine (Hcy) could lead to endothelial dysfunction and is viewed as an independent risk factor for atherosclerosis. Heat shock protein 27 (HSP27), a small heat shock protein, is reported to exert protective effect against atherosclerosis. This study aims to investigate the protective effect of HSP27 against Hcy-induced endothelial cell apoptosis in human umbilical vein endothelial cells (HUVECs) and to determine the underlying mechanisms. Methods. Apoptosis, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) of normal or HSP27-overexpressing HUVECs in the presence of Hcy were analyzed by flow cytometry. The mRNA and protein expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Results. We found that Hcy could induce cell apoptosis with corresponding decrease of nitric oxide (NO) level, increase of endothelin-1 (ET-1), intracellular adhesion molecule-1 (ICAM-1), vascular cellular adhesion molecule-1 (VCAM-1), and monocyte chemoattractant protein-1 (MCP-1) levels, elevation of ROS, and dissipation of MMP. In addition, HSP27 could protect the cell against Hcy-induced apoptosis and inhibit the effect of Hcy on HUVECs. Furthermore, HSP27 could increase the ratio of Bcl-2/Bax and inhibit caspase-3 activity. Conclusions. Therefore, we concluded that HSP27 played a protective role against Hcy-induced endothelial apoptosis through modulation of ROS production and the mitochondrial caspase-dependent apoptotic pathway.

Costunolide Induces Apoptosis through Generation of ROS and Activation of P53 in Human Esophageal Cancer Eca-109 Cells

Costunolide is a sesquiterpene lactone, which possesses potent anti-cancer properties. However, there is little report about its effects on esophageal cancer. In our study, we investigated the effects of costunolide on the cell viability, cell cycle, and apoptosis in human esophageal cancer Eca-109 cells. It was found that costunolide inhibited the growth of Eca-109 cells in a dose-dependent manner, which was associated with the loss of mitochondrial membrane potential (Δψm ) and the production of ROS. Costunolide induced apoptosis of Eca-109 cells as well as cell cycle arrest in G1/S phase by upregulation of P53 and P21. Costunolide triggered apoptosis in esophageal cancer cells via the upregulation of Bax, downregulation of Bcl-2, and significant activation of caspase-3 and poly ADP-ribose polymerase. These effects were markedly abrogated when cells were pretreated with N-acetylcysteine, a specific reactive oxygen specie inhibitor. These results suggest that costunolide is a potential candidate for the treatment of esophageal cancer.

Acetogenins from Annona muricata as potential inhibitors of antiapoptotic proteins: a molecular modeling study

Apoptosis is a highly regulated process crucial for maintaining cellular homeostasis and development. The B-cell lymphoma 2 (Bcl-2) family of proteins play a crucial role in regulating apoptosis. Overexpressed Bcl-2 proteins are associated with the development and progression of several human cancers. Annona muricata is a tropical plant that belongs to the Annonaceae family and is well known for its anticancer properties. In this study, molecular docking and simulations were performed to investigate the inhibitory potential of phytochemicals present in A. muricata against antiapoptotic proteins of the Bcl-2 family including Bcl-2, B-cell lymphoma extra-large (Bcl-Xl), and Mcl-1. Docking results revealed that the acetogenins, such as annomuricin A, annohexocin, muricatocin A, annomuricin-D-one, and muricatetrocin A/B, exhibited strong binding interactions with Bcl-Xl when compared to Bcl-2 and Mcl-1. Binding score and interactions of these acetogenins were notably better than those of currently available synthetic and natural inhibitors. Molecular dynamics simulations of the top-scoring lead molecules established that these molecules could bind strongly and consistently in the active site of Bcl-Xl. These results suggest that acetogenins could be explored as selective natural inhibitors of Bcl-Xl that could assist in promoting the intrinsic pathway of apoptosis.

Major apoptotic mechanisms and genes involved in apoptosis

As much as the cellular viability is important for the living organisms, the elimination of unnecessary or damaged cells has the opposite necessity for the maintenance of homeostasis in tissues, organs and the whole organism. Apoptosis, a type of cell death mechanism, is controlled by the interactions between several molecules and responsible for the elimination of unwanted cells from the body. Apoptosis can be triggered by intrinsically or extrinsically through death signals from the outside of the cell. Any abnormality in apoptosis process can cause various types of diseases from cancer to auto-immune diseases. Different gene families such as caspases, inhibitor of apoptosis proteins, B cell lymphoma (Bcl)-2 family of genes, tumor necrosis factor (TNF) receptor gene superfamily, or p53 gene are involved and/or collaborate in the process of apoptosis. In this review, we discuss the basic features of apoptosis and have focused on the gene families playing critical roles, activation/inactivation mechanisms, upstream/downstream effectors, and signaling pathways in apoptosis on the basis of cancer studies. In addition, novel apoptotic players such as miRNAs and sphingolipid family members in various kind of cancer are discussed.

Costunolide induces G1/S phase arrest and activates mitochondrial-mediated apoptotic pathways in SK-MES 1 human lung squamous carcinoma cells

Despite the availability of several therapeutic options, a safer and more effective modality strategy is required for the treatment of lung cancer. Costunolide, a sesquiterpene lactone which isolated from the Saussurea lappa, has potent anticancer properties. In the present study, the effects of costunolide on cell viability, the cell cycle and apoptosis in SK-MES-1 human lung squamous carcinoma cells were investigated. Costunolide induced morphological changes and inhibited growth of SK-MES-1 cells growth. Flow cytometric analysis data demonstrated that costunolide significantly induced apoptosis of SK-MES-1 cells and induced cell cycle arrest at G1/S phase in a dose-dependent manner. Through upregulation in the expression of p53 and Bax, and downregulation in the expression of Bcl-2 and activation of caspase-3, costunolide-induced apoptosis was confirmed by western blot analysis. In addition, the significant loss of mitochondrial membrane potential indicated that costunolide may induce apoptosis via the mitochondria-dependent pathway in SK-MES-1 cells. These results highlight the potential effects of costunolide as an anti-cancer agent in a human lung squamous carcinoma cell line.