Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Subtraction hybridization identified melanoma differentiation associated gene-7, mda-7, in the context of terminally differentiated human melanoma cells. Based on its structure, cytokine-like properties and proposed mode of action, mda-7 has now been classified as IL-24. When expressed by means of a replication-incompetent adenovirus, Ad.mda-7 induces apoptosis in a broad range of cancer cells, without inducing harmful effects in normal fibroblast or epithelial cells. These unique properties of mda-7/IL-24 suggest that this gene will prove beneficial for cancer gene therapy. We now demonstrate that Ad.mda-7 decreases viability by induction of apoptosis in hormone-responsive (LNCaP) and hormone-independent (DU-145 and PC-3) human prostate carcinomas, without altering growth or survival in early-passage normal human prostate epithelial cells (HuPEC). Ad.mda-7 causes G(2)/M arrest and apoptosis in LNCaP (p53-wildtype), DU-145 (p53 mutant, Bax-negative) and PC-3 (p53-negative) prostate carcinomas, but not in HuPEC. Apoptosis induction correlated with changes in the ratio of pro- to antiapoptotic Bcl-2 protein family members. A potential functional role for changes in bcl-2 family gene expression in Ad.mda-7-induced apoptosis was suggested by the finding that forced overexpression of bcl-x(L) or bcl-2 differentially diminished the apoptotic effect of Ad.mda-7 in prostate carcinomas. These results confirm that induction of apoptosis by the mda-7/IL-24 gene in prostate cancer cells is Bax- and p53-independent and is mediated by mitochondrial pathways involving bcl-2 family gene members. The mda-7/IL-24 gene represents a new class of cancer-specific apoptosis-inducing genes with obvious potential for the targeted gene-based therapy of human prostate cancer.
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PMID:Bcl-2 and Bcl-x(L) differentially protect human prostate cancer cells from induction of apoptosis by melanoma differentiation associated gene-7, mda-7/IL-24. 1464 71

Mda-7/IL-24 (Ad.mda-7) is a novel cytokine gene belonging to the interleukin (IL) 10 gene superfamily. Adenoviral-mediated delivery of mda-7/IL-24 causes growth suppression and apoptosis in a wide spectrum of cancer cells, including prostate, without harming normal cells. We now demonstrate that Ad.mda-7 selectively induces apoptosis in prostate cancer cells by promoting mitochondrial dysfunction and reactive oxygen species (ROS) production. Antioxidants (N-acetyl-L-cysteine and Tiron) and inhibitors of mitochondrial permeability transition (cyclosporine A and bongkrekic acid) inhibit Ad.mda-7-induced mitochondrial dysfunction and apoptosis. Conversely, agents augmenting ROS production (arsenic trioxide, NSC656240, and PK11195) facilitate Ad.mda-7-induced apoptosis. Ectopic expression of Bcl-2 and Bcl-x(L) inhibits mitochondrial changes, ROS production, and apoptosis providing additional support for an association between mitochondrial dysfunction and Ad.mda-7 action. These studies present definitive evidence that changes in mitochondrial function and ROS production are key components associated with selective killing of prostate cancer cells by mda-7/IL-24.
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PMID:Melanoma differentiation associated gene-7, mda-7/interleukin-24, induces apoptosis in prostate cancer cells by promoting mitochondrial dysfunction and inducing reactive oxygen species. 1467 67

Chronic lymphocytic leukemia (CLL)-B-cells are quiescent differentiated cells that produce interleukin (IL)-10 and accumulate due to resistance to apoptosis. The mechanisms underlying such resistance are poorly understood. Herein we show that all CLL B-cells tested (30/30) display high mRNA and protein expression of the tumor suppressor Mda-7/IL-24, an IL-10 family member, in comparison to normal B cells. A downstream Mda-7 signaling target, p38 mitogen-activated protein kinase (MAPK) was highly phosphorylated in all CLL cells but not in normal B-cells. Mda-7 expression and p38 MAPK phosphorylation diminished in culture and the latter could be reinduced by recombinant (r)-IL-24 or LPS and Mda-7 transfection. Mda-7/IL-24 siRNA specifically inhibited p38 MAPK phosphorylation in CLL without affecting p38 MAPK, bcl2, or Lyn expression, further demonstrating the direct role of Mda-7/IL-24 in p38 MAPK activation. Both pharmacological inhibition of p38 MAPK and Mda-7 silencing augmented spontaneous apoptosis by three-fold in CLL cells cultured in autologous serum, which was reversed by LPS and r-IL-24. We established the role of p38 MAPK in CLL cell survival and demonstrated a paradoxical effect, whereby Mda-7 and IL-24, inducers of apoptosis in diverse cancer cells, promote the survival of CLL B-cells through p38 MAPK activation.
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PMID:High Mda-7 expression promotes malignant cell survival and p38 MAP kinase activation in chronic lymphocytic leukemia. 1640 1

Terminal prostate cancer is refractory to conventional anticancer treatments because of frequent overexpression of antiapoptotic proteins Bcl-2 and/or Bcl-x(L). Adenovirus-mediated delivery of melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24), a secreted cytokine having cancer-selective apoptosis-inducing properties, profoundly inhibits prostate cancer cell growth. However, forced overexpression of Bcl-2 or Bcl-x(L) renders prostate cancer cells resistant to Ad.mda-7. We constructed a conditionally replication-competent adenovirus in which expression of the adenoviral E1A gene, necessary for replication, is driven by the cancer-specific promoter of progression elevated gene-3 (PEG-3) and which simultaneously expresses mda-7/IL-24 in the E3 region of the adenovirus (Ad.PEG-E1A-mda-7), a cancer terminator virus (CTV). This CTV generates large quantities of MDA-7/IL-24 as a function of adenovirus replication uniquely in cancer cells. Infection of Ad.PEG-E1A-mda-7 (CTV) in normal prostate epithelial cells and parental and Bcl-2- or Bcl-x(L)-overexpressing prostate cancer cells confirmed cancer cell-selective adenoviral replication, mda-7/IL-24 expression, growth inhibition, and apoptosis induction. Injecting Ad.PEG-E1A-mda-7 (CTV) into xenografts derived from DU-145-Bcl-x(L) cells in athymic nude mice completely eradicated not only primary tumors but also distant tumors (established in the opposite flank), thereby implementing a cure. These provocative findings advocate potential therapeutic applications of this novel virus for advanced prostate cancer patients with metastatic disease.
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PMID:Eradication of therapy-resistant human prostate tumors using a cancer terminator virus. 1754 25

Previous studies have demonstrated that interleukin-24 [IL-24; originally called melanoma differentiation associated gene-7 (mda-7)] as a novel tumor suppressor gene has tumor-suppressive activity against a broad spectrum of human cancers. However, the therapeutic effect of the recombinant human IL-24 (rhIL-24) protein purified from prokaryotic cells on gastric cancer has not been reported. In this study, we purified soluble rhIL-24 using Q-Sepharose column after the denaturing and renaturing process from the protein of Escherichia coli BL21 transfected with pET-21a(+)-hIL-24 vector and treated by isopropyl-beta-D-1-thiogalactopyranoside (IPTG) for enhanced expression of transgene rhIL-24. We demonstrated that rhIL-24 was capable of inducing in vitro apoptosis of SGC7901 gastric cancer cells and activating peripheral blood mononuclear cellsto secrete cytokines such as IL-6, TNF-alpha, and IFN-gamma. We also showed that rhIL-24 was able to inhibit formation of blood capillaries on chicken embryonic allantois and in vivo tumor angiogenesis leading to suppressing SGC7901 gastric cancer cell growth in vitro and in vivo possibly due to its downregulation of Bcl-2/Bax ratio, VEGF (vascular endothelial growth factor), and CD34. Therefore, our results indicate that rhIL-24 has potent suppressive effect on human SGC7901 gastric carcinoma cell line and warrant its further investigation for therapeutic application against gastric cancer.
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PMID:Recombinant human interleukin-24 suppresses gastric carcinoma cell growth in vitro and in vivo. 1991 46

Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24), a cytokine belonging to the IL-10 family, selectively induces apoptosis in cancer cells without harming normal cells by promoting an endoplasmic reticulum (ER) stress response. The precise molecular mechanism by which the ER stress response culminates in cell death requires further clarification. The present study shows that in prostate carcinoma cells, the mda-7/IL-24-induced ER stress response causes apoptosis by translational inhibition of the antiapoptotic protein myeloid cell leukemia-1 (Mcl-1). Forced expression of Mcl-1 blocked mda-7/IL-24 lethality, whereas RNA interference or gene knockout of Mcl-1 markedly sensitized transformed cells to mda-7/IL-24. Mcl-1 downregulation by mda-7/IL-24 relieved its association with the proapoptotic protein Bak, causing oligomerization of Bak and leading to cell death. These observations show the profound role of the Bcl-2 protein family member Mcl-1 in regulating cancer-specific apoptosis induced by this cytokine. Thus, our studies provide further insights into the molecular mechanism of ER stress-induced cancer-selective apoptosis by mda-7/IL-24. As Mcl-1 is overexpressed in the majority of prostate cancers, mda-7/IL-24 might provide an effective therapeutic for this disease.
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PMID:Mechanism by which Mcl-1 regulates cancer-specific apoptosis triggered by mda-7/IL-24, an IL-10-related cytokine. 2050 29

mda-7/IL-24 has tumor-suppressor activity in a broad spectrum of human cancer cells. However, the therapeutic effect of the recombinant human IL-24 protein on human gallbladder carcinoma has rarely been explored. In this study, we used a human gallbladder carcinoma cell line (GBC-SD) to explore the effect of adenovirus-mediated IL-24 (Ad-IL24) gene therapy on GBC-SD cells. We show that Ad-IL24 treatment of GBC-SD cells in vitro conspicuously induced apoptosis of GBC-SD cells. We also demonstrate that the in vivo treatment of GBC tumor-bearing athymic nude mice intratumorally injected with Ad-IL24 significantly suppressed GBC growth. To further explore the mechanism that mda-7/IL-24 utilized in tumor cell apoptosis, we examined molecules and pathways involved in apoptotic regulation and found that Ad-IL24 induced the down-regulation of anti-apoptotic gene Bcl-2 and the release of cytochrome c, which subsequently activated caspase-9, caspase-3 and PARP to induce apoptosis. In summary, adenovirus (AdV)-mediated IL-24 overexpression exerted potent antitumor activity via stimulating mitochondrial apoptotic pathway in GBC-SD. Therefore, mda-7/IL-24 has the potential to serve as a tool for targeted gene therapy in the treatment of gallbladder cancer.
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PMID:mda-7/IL-24 induces apoptosis in human GBC-SD gallbladder carcinoma cells via mitochondrial apoptotic pathway. 2110 77

Limited options are available for treating patients with advanced prostate cancer (PC). Melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24), an IL-10 family cytokine, exhibits pleiotropic anticancer activities without adversely affecting normal cells. We previously demonstrated that suppression of the prosurvival Bcl-2 family member, myeloid cell leukemia-1 (Mcl-1), is required for mda-7/IL-24-mediated apoptosis of prostate carcinomas. Here we demonstrate that pharmacological inhibition of Mcl-1 expression with the unique Apogossypol derivative BI-97C1, also called Sabutoclax, is sufficient to sensitize prostate tumors to mda-7/IL-24-induced apoptosis, whereas ABT-737, which lacks efficacy in inhibiting Mcl-1, does not sensitize mda-7/IL-24-mediated cytotoxicity. A combination regimen of tropism-modified adenovirus delivered mda-7/IL-24 (Ad.5/3-mda-7) and BI-97C1 enhances cytotoxicity in human PC cells, including those resistant to mda-7/IL-24 or BI-97C1 alone. The combination regimen causes autophagy that facilitates NOXA- and Bim-induced and Bak/Bax-mediated mitochondrial apoptosis. Treatment with Ad.5/3-mda-7 and BI-97C1 significantly inhibits the growth of human PC xenografts in nude mice and spontaneously induced PC in Hi-myc transgenic mice. Tumor growth inhibition correlated with increased TUNEL staining and decreased Ki-67 expression in both PC xenografts and prostates of Hi-myc mice. These findings demonstrate that pharmacological inhibition of Mcl-1 with the Apogossypol derivative, BI-97C1, sensitizes human PCs to mda-7/IL-24-mediated cytotoxicity, thus potentially augmenting the therapeutic benefit of this combinatorial approach toward PC.
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PMID:Apogossypol derivative BI-97C1 (Sabutoclax) targeting Mcl-1 sensitizes prostate cancer cells to mda-7/IL-24-mediated toxicity. 2853 99

Adenovirus (Ad)-based gene therapy represents a potentially viable strategy for treating colorectal cancer. The infectivity of serotype 5 adenovirus (Ad.5), routinely used as a transgene delivery vector, is dependent on Coxsackie-adenovirus receptors (CAR). CAR expression is downregulated in many cancers thus preventing optimum therapeutic efficiency of Ad.5-based therapies. To overcome the low CAR problem, a serotype chimerism approach was used to generate a recombinant Ad (Ad.5/3) that is capable of infecting cancer cells via Ad.3 receptors in a CAR-independent manner. We evaluated the improved transgene delivery and efficacy of Ad.5/3 recombinant virus expressing melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24), an effective wide-spectrum cancer-selective therapeutic. In low CAR human colorectal cancer cells RKO, wild-type Ad.5 virus expressing mda-7/IL-24 (Ad.5-mda-7) failed to infect efficiently resulting in lack of expression of MDA-7/IL-24 or induction of apoptosis. However, a recombinant Ad.5/3 virus expressing mda-7/IL-24 (Ad.5/3-mda-7) efficiently infected RKO cells resulting in higher MDA-7/IL-24 expression and inhibition of cell growth both in vitro and in nude mice xenograft models. Addition of the novel Bcl-2 family pharmacological inhibitor Apogossypol derivative BI-97C1 (Sabutoclax) significantly augmented the efficacy of Ad.5/3-mda-7. A combination regimen of suboptimal doses of Ad.5/3-mda-7 and BI-97C1 profoundly enhanced cytotoxicity in RKO cells both in vitro and in vivo. Considering the fact that Ad.5-mda-7 has demonstrated significant objective responses in a Phase I clinical trial for advanced solid tumors, Ad.5/3-mda-7 alone or in combination with BI-97C1 would be predicted to exert significantly improved therapeutic efficacy in colorectal cancer patients.
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PMID:Enhanced delivery of mda-7/IL-24 using a serotype chimeric adenovirus (Ad.5/3) in combination with the Apogossypol derivative BI-97C1 (Sabutoclax) improves therapeutic efficacy in low CAR colorectal cancer cells. 2178 Jan 16

MDA-7/IL-24 was involved in the specific cancer apoptosis through suppression of Bcl-2 expression, which is a key apoptosis regulatory protein of the mitochondrial death pathway. However, the underlying mechanisms of this regulation are unclear. We report here that tumor-selective replicating adenovirus ZD55-IL-24 leads to Bcl-2 S-denitrosylation and concomitant ubiquitination, which take part in the 26S proteasome degradation. IL-24-siRNA completely blocks Bcl-2 ubiquitination via reversion of Bcl-2 S-denitrosylation and protects it from proteasomal degradation which confirmed the significant role of MDA-7/IL-24 in regulating posttranslational modification of Bcl-2 in cancer cells. Nitric oxide (NO) is a key regulator of protein S-nitrosylation and denitrosylation. The NO donor, sodium nitroprusside (SNP), down-regulates Bcl-2 S-denitrosylation, attenuates Bcl-2 ubiquitination and subsequently counteracts MDA-7/IL-24 induced cancer cell apoptosis, whereas NO inhibitor 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxy-3-oxide (PTIO) shows the opposite effect. At the same time, these NO modulators fail to affect Bcl-2 phosphorylation, suggesting that NO regulates Bcl-2 stability in a phosphorylation-independent manner. In addition, Bcl-2 S-nitrosylation reduction induced by ZD55-IL-24 was attributed to both iNOS decrease and TrxR1 increase. iNOS-siRNA facilitates Bcl-2 S-denitrosylation and ubiquitin-degradation, whereas the TrxR1 inhibitor auranofin prevents Bcl-2 from denitrosylation and ubiquitination, thus restrains the caspase signal pathway activation and subsequent cancer cell apoptosis. Taken together, our studies reveal that MDA-7/IL-24 induces Bcl-2 S-denitrosylation via regulation of iNOS and TrxR1. Moreover, denitrosylation of Bcl-2 results in its ubiquitination and subsequent caspase protease family activation, as a consequence, apoptosis susceptibility. These findings provide a novel insight into MDA-7/IL-24 induced growth inhibition and carcinoma apoptosis.
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PMID:MDA-7/IL-24 induces Bcl-2 denitrosylation and ubiquitin-degradation involved in cancer cell apoptosis. 2262 68


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