withanolides and Kidney-Neoplasms

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Biological Products; Carcinoma, Renal Cell; Cell Cycle Proteins; Cell Proliferation; Drug Therapy, Combination; Female; Humans; Immunotherapy; Interferon Inducers; Kidney Neoplasms; Male; Melanoma, Experimental; Mice; Mice, Inbred BALB C; Mice, Nude; Poly I-C; Transcription Factors; Tumor Cells, Cultured; Withanolides; Xenograft Model Antitumor Assays

Investigation of aeroponically grown Physalis peruviana resulted in the isolation of 11 new withanolides, including perulactones I-L (1-4), 17-deoxy-23β-hydroxywithanolide E (5), 23β-hydroxywithanolide E (6), 4-deoxyphyperunolide A (7), 7β-hydroxywithanolide F (8), 7β-hydroxy-17-epi-withanolide K (9), 24,25-dihydro-23β,28-dihydroxywithanolide G (10), and 24,25-dihydrowithanolide E (11), together with 14 known withanolides (12-25). The structures of 1-11 were elucidated by the analysis of their spectroscopic data, and 12-25 were identified by comparison of their spectroscopic data with those reported. All withanolides were evaluated for their cytotoxic activity against a panel of tumor cell lines including LNCaP (androgen-sensitive human prostate adenocarcinoma), 22Rv1 (androgen-resistant human prostate adenocarcinoma), ACHN (human renal adenocarcinoma), M14 (human melanoma), SK-MEL-28 (human melanoma), and normal human foreskin fibroblast cells. Of these, the 17β-hydroxywithanolides (17-BHWs) 6, 8, 9, 11-13, 15, and 19-22 showed selective cytotoxic activity against the two prostate cancer cell lines LNCaP and 22Rv1, whereas 13 and 20 exhibited selective toxicity for the ACHN renal carcinoma cell line. These cytotoxicity data provide additional structure-activity relationship information for the 17-BHWs.

Topics: Antineoplastic Agents, Phytogenic; Drug Screening Assays, Antitumor; Humans; Kidney Neoplasms; Male; Melanoma; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Physalis; Prostatic Neoplasms; Structure-Activity Relationship; Withanolides

Renal cell carcinoma (RCC) is a cancer with poor prognosis, and the 5-year survival rate of patients with metastatic RCC is 5-10%. Consequently, treatment of metastatic RCC represents an unmet clinical need. Screening of a 50 000-member library of natural and synthetic compounds for sensitizers of RCC cells to TRAIL-mediated apoptosis led to identification of the 17β-hydroxywithanolide (17-BHW), withanolide E (1), as a promising lead. To explore structure-activity relationships, we obtained natural and semisynthetic withanolides 1, 2a, 2c, and 3-36 and compared their ability to sensitize TRAIL-mediated apoptosis in a panel of renal carcinoma cells. Our findings revealed that 17-BHWs with a α-oriented side chain are superior to known TRAIL-sensitizing withanolides belonging to withaferin A class with a β-oriented side chain and demonstrated that the 17-BHW scaffold can be modified to enhance sensitization of RCCs to TRAIL-mediated apoptosis, thereby assisting development of natural-product-inspired drugs to treat metastatic RCC.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Renal Cell; Cell Line, Tumor; Ergosterol; Humans; Kidney; Kidney Neoplasms; Structure-Activity Relationship; TNF-Related Apoptosis-Inducing Ligand; Withania; Withanolides

Sixteen new withanolides, physangulatins A-N (1-14) and withaphysalins Y and Z (15 and 16), as well as 12 known analogues, were isolated from the stems and leaves of Physalis angulata L. Their structures were established using extensive spectroscopic data analyses. The absolute configurations of 1 and 9 were assigned via X-ray crystallography. The isolated compounds were tested for their antiproliferative effects against human prostate cancer cells (C4-2B and 22Rvl), human renal carcinoma cells (786-O, A-498, and ACHN), and human melanoma cells (A375-S2), as well as inhibitory effects on NO production induced by LPS in macrophages. Compounds 9, 17, 20, 21, 25, and 27 showed antiproliferative effects against all tested cancer cells, with IC50 values of 0.18-7.43 μM. Compounds 3-5, 9-11, 17, 20-22, 24, 25, and 27 displayed inhibitory effects against NO production, with IC50 values of 1.36-11.59 μM.

Topics: Anti-Inflammatory Agents; Antineoplastic Agents, Phytogenic; Crystallography, X-Ray; Drug Screening Assays, Antitumor; Drugs, Chinese Herbal; Humans; Inhibitory Concentration 50; Kidney Neoplasms; Lipopolysaccharides; Macrophages; Male; Molecular Conformation; Molecular Structure; Nitric Oxide; Nuclear Magnetic Resonance, Biomolecular; Physalis; Plant Leaves; Plant Stems; Prostatic Neoplasms; Withanolides

We have purified physapubescin, a predominant steroidal lactone, from medicinal plant Physalis pubescens L., commonly named as "hairy groundcherry" in English and "Deng-Long-Cao" in Chinese. Von Hippel-Lindau (VHL)-null 786-O, RCC4 and A498 Renal Cell Carcinoma (RCC) cell lines expressing high levels of Hypoxia Inducible Factor (HIF)-2α are more sensitive to physapubescin-mediated apoptosis and growth inhibitory effect than VHL wild-type Caki-2 and ACHN RCC cell lines. Restoration of VHL in RCC4 cells attenuated the growth inhibitory effect of physapubescin. Physapubescin decreases the expression of HIF-2α and increases the expression of CCAAT/enhancer-binding protein homologus protein (CHOP), which leads to up-regulation of death receptor 5 (DR5), activation of caspase-8 and -3, cleavage of poly (ADP-Ribose) polymerase (PARP) and apoptosis. Under hypoxia conditions, the apoptotic and growth inhibitory effects of physapubescin are further enhanced. Additionally, physapubescin synergizes with TNF-related apoptosis-inducing ligand (TRAIL) for markedly enhanced induction of apoptosis in VHL-null 786-O cells but not in VHL wild-type Caki-2 cells. Physapubescin significantly inhibited in vivo angiogenesis in the 786-O xenograft. Physapubescin as a novel agent for elimination of VHL-null RCC cells via apoptosis is warranted for further investigation.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Renal Cell; Caspase 3; Caspase 8; Cell Line, Tumor; Gene Deletion; Gene Expression Regulation, Neoplastic; Humans; Hypoxia; Kidney Neoplasms; Mice; Mice, Nude; Neovascularization, Pathologic; Physalis; Poly(ADP-ribose) Polymerases; Receptors, TNF-Related Apoptosis-Inducing Ligand; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand; Transcription Factor CHOP; Tumor Burden; Von Hippel-Lindau Tumor Suppressor Protein; Withanolides; Xenograft Model Antitumor Assays

The accumulation of misfolded proteins in the lumen of the endoplasmic reticulum (ER) results in cellular stress that initiates a specialized response designated as the unfolded protein response. ER stress has been implicated in a variety of common diseases, such as diabetes, ischemia and neurodegenerative disorders. Withaferin A, a major chemical constituent of Withania somnifera, has been reported to inhibit tumor cell growth. We show that withaferin A induced a dose-dependent apoptotic cell death in several types of human cancer cells, as measured by FACS analysis and PARP cleavage. Treatment of Caki cells with withaferin A induced a number of signature ER stress markers, including phosphorylation of eukaryotic initiation factor-2α (eIF-2 α), ER stress-specific XBP1 splicing, and up-regulation of glucose-regulated protein (GRP)-78. In addition, withaferin A caused up-regulation of CAAT/enhancer-binding protein-homologous protein (CHOP), suggesting the induction of ER stress. Pretreatment with N-acetyl cysteine (NAC) significantly inhibited withaferin A-mediated ER stress proteins and cell death, suggesting that reactive oxygen species (ROS) mediate withaferin A-induced ER stress. Furthermore, CHOP siRNA or inhibition of caspase-4 activity attenuated withaferin A-induced apoptosis. Taken together, the present study provides strong evidence supporting an important role of the ER stress response in mediating withaferin A-induced apoptosis.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Renal Cell; Cell Nucleus; Cell Proliferation; Cell Survival; DNA-Binding Proteins; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Endoplasmic Reticulum, Rough; Gene Silencing; HT29 Cells; Humans; Kidney Neoplasms; Oxidative Stress; Regulatory Factor X Transcription Factors; RNA, Messenger; RNA, Small Interfering; Transcription Factor CHOP; Transcription Factors; Withanolides; X-Box Binding Protein 1