Withanolide D of Ashwagandha improves Apoptosis in the Bone Marrow of Leukemic Murine Model

Background: Leukemia is one of the most occurring haematological pathologies in the world which develops due to the impairment in the hematopoietic machinery. Cellular death via apoptosis is severely impaired in this pathophysiological condition and leads to the progression of the disease. Objective: We have tried to unearth the efficacy of Withanolide D, a steroidal lactone derived from Withania somnifera or Ashwagandha on some of the apoptotic machinery components, i.e. TERT, BCL2 and PUMA in the experimental leukemic mice. Materials and Methods: LD50 and EC50 values of Withanolide D were estimated. Three groups of animals were taken for experimental purpose i.e. Group I = Leukemic, (L); Group II = Control, (C); Group III = Leukemic treated with Withanolide D, (L + WD). Group III received Withanolide D via oral route and other two groups received equal volume of distilled water. Various cytological, immunofluorescence and flow cytometric studies were taken into consideration post administration. Result: Leukemic group showed increased cellular proliferation and decreased cellular death as compared to control. Post Withanolide D administration TERT, BCL2 and PUMA expression started to shift towards normal status. This shift in the expressional values of increased apoptosis rate and decreased cellular proliferation revealed by cytological, immunofluorescence studies and flow cytometric investigations. Conclusion: As Withanolide D decreased the suppression of apoptosis and impaired the progression of the disease, so, we can conclude that Withanolide D of Ashwagandha may hold a promise towards a new therapeutic strategy in leukemia.

PUMA mediated afatinib-induced apoptosis in glioma cells

IntroductionAfatinib exhibits a tumor-inhibiting effect in different cancers by inducing apoptosis; however, its pro-apoptosis role in glioma cells is still not fully understood.Material and methodsIn the current study, two glioma cell lines (U373-MG and U87-MG) were treated with afatinib to measure their tolerance for afatinib-triggered cell death and apoptosis.ResultsWe found that afatinib treatment repressed both growth and proliferation and induced apoptosis in glioma cells. Moreover, it increased the expression of pro-apoptotic p53-upregulated modulator of apoptosis (PUMA). The influence of PUMA on afatinib-triggered apoptosis was assessed by PUMA overexpression and knockdown in glioma cell lines. PUMA overexpression resulted in an increased sensitivity of glioma cell lines toward afatinib, whereas its knockdown abated the effect of afatinib on apoptosis. Similarly, the in vivo potency of afatinib on U373-MG xenograft tumors in wild type (WT) and PUMA knockdown nude mice was measured. Afatinib treatment reduced the weight and volume of WT xenograft tumors but did not have the same effect on PUMA knockdown xenograft tumors. Afatinib also induced significant cell death and apoptosis in WT xenograft tumors but not in PUMA knockdown xenograft tumors.ConclusionsIn conclusion, afatinib induces apoptosis in glioma cells by mediating PUMA expression. This study warrants further investigation into the mechanism of afatinib in glioblastoma treatment.

Copanlisib promotes growth inhibition and apoptosis by modulating the AKT/FoxO3a/PUMA axis in colorectal cancer

Colorectal cancer (CRC) is the type of cancer with the third highest incidence and is associated with high mortality and low 5-year survival rates. We observed that copanlisib, an inhibitor of PI3K (pan-class I phosphoinositide 3-kinase) that preferentially inhibits PI3Kδ and PI3Kα, impedes the growth of CRC cells by inducing apoptosis via PUMA. There was a marked increase in the expression of PUMA independent of p53 after treatment with copanlisib. The response of CRC cells to copanlisib could be predicted by PUMA expression. Copanlisib was found to induce PUMA expression through FoxO3a by directly binding to the PUMA promoter after inhibiting AKT signaling. PUMA deficiency mitigated the apoptosis induced by copanlisib. Caspase activation and mitochondrial dysfunction led to copanlisib resistance, as observed through a clonogenic assay, whereas enhanced expression of PUMA increased the copanlisib-induced susceptibility to apoptosis. Moreover, the antitumor effects of copanlisib were suppressed by a deficiency of PUMA in a xenograft model, and caspase activation and reduced apoptosis were also observed in vivo. Copanlisib-mediated chemosensitization seemed to involve the concurrent induction of PUMA expression via mechanisms that were both dependent and independent of p53. These observations indicate that apoptosis mediated by PUMA is crucial for the anticancer effects of copanlisib and that manipulation of PUMA may aid in enhancing anticancer activities.

PUMA and NOXA Expression in Tumor-Associated Benign Prostatic Epithelial Cells Are Predictive of Prostate Cancer Biochemical Recurrence

Background: Given that treatment decisions in prostate cancer (PC) are often based on risk, there remains a need to find clinically relevant prognostic biomarkers to stratify PC patients. We evaluated PUMA and NOXA expression in benign and tumor regions of the prostate using immunofluorescence techniques and determined their prognostic significance in PC. Methods: PUMA and NOXA expression levels were quantified on six tissue microarrays (TMAs) generated from radical prostatectomy samples (n = 285). TMAs were constructed using two cores of benign tissue and two cores of tumor tissue from each patient. Association between biomarker expression and biochemical recurrence (BCR) at 3 years was established using log-rank (LR) and multivariate Cox regression analyses. Results: Kaplan–Meier analysis showed a significant association between BCR and extreme levels (low or high) of PUMA expression in benign epithelial cells (LR = 8.831, p = 0.003). Further analysis revealed a significant association between high NOXA expression in benign epithelial cells and BCR (LR = 14.854, p < 0.001). The combination of extreme PUMA and high NOXA expression identified patients with the highest risk of BCR (LR = 16.778, p < 0.001) in Kaplan–Meier and in a multivariate Cox regression analyses (HR: 2.935 (1.645–5.236), p < 0.001). Conclusions: The combination of PUMA and NOXA protein expression in benign epithelial cells was predictive of recurrence following radical prostatectomy and was independent of PSA at diagnosis, Gleason score and pathologic stage.

PI3K/Akt and ERK1/2 Signalling Are Involved in Quercetin-Mediated Neuroprotection against Copper-Induced Injury

Copper, a transition metal with essential cellular functions, exerts neurotoxic effects when present in excess by promoting production of reactive oxygen species (ROS). The aim of the present study was to investigate potential benefits of flavonoid quercetin against copper-induced toxicity. Results obtained with MTT assay indicate that the effects of quercetin are determined by the severity of the toxic insult. In moderately injured P19 neuronal cells, concomitant treatment with 150 μM quercetin improved viability by preventing ROS formation, caspase-3 activation, and chromatin condensation. Western blot analysis revealed that quercetin reduced copper-induced increase in p53 upregulated modulator of apoptosis (PUMA) expression and promoted upregulation of nucleoside diphosphate kinase NME1. Levels of p53 and Bax proteins were not affected by both copper and quercetin. UO126 and wortmannin, inhibitors of ERK1/2 and PI3K/Akt signalling pathways, respectively, prevented neuroprotective effects of quercetin. In severely injured neurons, 30 μM quercetin exerted strong prooxidative action and exacerbated cytotoxic effects of copper, whereas 150 μM quercetin failed to affect neuronal survival. These results demonstrate the dual nature of quercetin action in copper-related neurodegeneration. Hence, they are relevant in the context of considering quercetin as a possible therapeutic for neuroprotection and imply that detailed pharmacological and toxicological studies must be carried out for natural compounds capable of acting both as antioxidants and prooxidants.

Follicle stimulating hormone inhibits the expression of p53 up-regulated modulator of apoptosis induced by reactive oxygen species through PI3K/Akt in mouse granulosa cells

In mammalian ovaries, follicular atresia occurs periodically and destroys almost all the follicles in the ovary. Follicle-stimulating hormone (FSH) acts as the primary survival factor during follicular atresia by preventing apoptosis in granulosa cells (GCs). Many studies have demonstrated that oxidative stress-induced apoptosis is a main cause of follicular atresia. Reactive oxygen species (ROS)-induced GCs apoptosis is regulated by a variety of signaling pathways involving numerous genes and transcription factors. Therefore, we examined whether FSH inhibits the expression of p53 up-regulated modulator of apoptosis (PUMA) induced by reactive oxygen species (ROS) through phosphoinositide 3-kinase (PI3K) / protein kinase B (AKT) in mouse GCs. In vivo study: thirty-two-mice were randomly assigned to four groups and given FSH. We found that FSH can inhibit the 3-nitropropionic acid (3-NP) induced apoptosis and PUMA expression in mRNA level. Moreover, In vitro experiment, we found that FSH can inhibit the H(2)O(2)-induced apoptosis and PUMA expression in mRNA level. Additionally, we also found that PI3K/AKT inhibitor LY294002 abolished the downregulation of PUMA mRNA by FSH in vitro, In conclusion, FSH inhibit the expression of PUMA induced by ROS through PI3K/AKT pathway in vivo and vitro.

Targeting MDM2 and XIAP By Idasanutlin in Diffuse Large B-Cell Lymphoma

Purpose: The combination of rituximab and chemotherapy has improved overall survival of diffuse large B-cell lymphoma (DLBCL) patients in recent decades. Relapsed/refractory DLBCL patients previously treated with rituximab-containing regimen had significantly poorer response to salvage therapy. To study the mechanisms of this resistance, our laboratory developed several rituximab resistant cell lines. Previous study from our group found demonstrated an aberrant imbalance in the levels of pro- and anti-apoptotic proteins in these cell lines, including Bak/Bak, Mcl-1/BCLxL/Survivin and inhibitor of apoptosis (IAP) family proteins resulting in acquired chemotherapy resistance. MDM2 is an E3 ligase which regulates the degradation of multiple cellular protein targets such as pRB, HIF-1, p73, NF-kB, and E2F1 as well as FOXO3a. It is also the major negative regulator of p53. Recently, we found that MX69 (a MDM2 inhibitor), which blocks the MDM2 protein-XIAP RNA interaction, led to both MDM2 and XIAP degradation, and induced apoptosis-dependent cell killing activity. Moreover, MX69 re-sensitized resistant DLBCL cell lines to chemotherapy agents or small inhibitors (i.e. Venetoclax) in vitro. However, MX69 cannot be used clinically stressing the need to use a clinically available MDM2 inhibitor. To this end, we evaluated Idasanutlin, an investigational Nutlin family MDM2 antagonist, in B-cell lymphoma pre-clinical models. Methods: We used a panel of different DLBCL subtypes cell lines including activated B-cell lymphoma cell lines (TMD8, U2932); germinal center B-cell lymphoma (DOHH2, VAL, OCILY2, DH4, DH6, ROS50); rituximab-sensitive cell lines (Raji and RL); and rituximab/-resistant cell lines (Raji 4RH and RL 4RH). Cells were exposed to escalating doses of Idasanutlin (1nM-100µM) without or with other chemotherapeutic agents for 24, 48 and 72 hrs. Differences in cell viability were evaluated utilizing PrestoBlue. IC50 was calculated by GraphPad and Coefficient of synergy was calculated using CalcuSyn. Low mitochondrial potential was detected by staining cell with DiOC6 10ng/ml for 30 minutes and followed by flow cytometric analysis. Western blot was used to detect the changes of MDM2, XIAP and PUMA expression before and after exposure to Idasanutlin 1uM for 24h. Results:In vitro exposure Idasanutlin to DLBCL cell lines demonstrated a dose- and time-dependent cell death. IC50 dosage of the cells was ranged from 0.7uM to 63.07uM at 48h. Low dose of Idasanutlin (1uM) was able to disrupt mitochondria and induced low mitochondrial membrane potential in both ABC and GCB cell lines. At molecular level, Idasanutlin reduced expression level of MDM2 in TMD8, U2932, VAL, OCILy2 DHL4 and ROS50 cell lines. XIAP was reduced in Val and DHL4. Meanwhile, PUMA, the downstream of p53 activation, was increased after Idasanutlin exposure. Idasanutlin enhanced the anti-tumor activity of proteasome inhibitors (carfilzomib, ixazomib), Bcl-2 inhibitor venetoclax and Bryton kinase inhibitor ibrutinib. Conclusion: Idasanutlin showed potent anti-tumor activity as a single agent in DLBCL pre-clinical setting. Idasanutlin was able to decrease cellular mitochondrial membrane potential. At molecular level, Idasanutlin decreased MDM2 and XIAP protein level and induced PUMA expression. Moreover, Idasanutlin enhanced anti-tumor activities of other small inhibitors. Taking together, Idasanutlin could be used as a novel and promising drug in the clinical setting of DLBCL with relapsed/refractory disease. Disclosures No relevant conflicts of interest to declare.