Curcumin rescue p53Y220C in BxPC-3 pancreatic adenocarcinomas cell line: Evidence-based on computational, biophysical, and in vivo studies.

BACKGROUND: The p53, tumor suppressor protein is inactivated upon mutation in the DNA-binding domain and the non-functional protein leads to cancers. The p53Y220C is one of the most frequently observed mutations in p53 with a scope of rescuing the protein function using small molecules. METHODS: Using computational modeling, biophysical, and experimental cell-based studies we tried to understand the molecular basis of Curcumin as a potential small molecule to stabilize p53Y220C mutant and restore its function. The pancreatic adenocarcinomas BxPC-3 p53Y220C mutant cell line was used for cell-based assays to determine the therapeutic potential of Curcumin to restore mutant p53 to function like wild type. RESULTS: Our results showed that the Curcumin binds p53Y220C with Kd = 3.169 ± 0.257 µM and it increases the DNA binding affinity of the mutant by 4-fold with Kd = 851.29 ± 186.27 nM. By Fluorescence, CD, and IR spectroscopy, we could characterize the secondary structural changes and stabilization of the p53Y220C DNA binding domain upon Curcumin binding. By caspase-3 and Annexin V assays, we could demonstrate that Curcumin at 3 µM to 8 µM concentration could initiate p53 mediated apoptosis in BxPC-3 cell line. Based on our experimental studies, we propose a mechanism for the activation of ATM/Chk1 kinases pathways for apoptosis and/or G2/M cell cycle arrest in the BxPC-3 cell line mediated by functionally restored p53Y220C. CONCLUSION: The study indicated that the natural compound Curcumin could rescue mutant p53Y220C in BxPC-3 pancreatic adenocarcinomas cell line to function like wild-type and activate apoptotic pathways.

A study on prostate movement and dosimetric variation because of bladder and rectum volumes changes during the course of image-guided radiotherapy in prostate cancer.

AIM: To study the impact of bladder and rectum volume changes on prostate positioning and the dosimetric parameters. BACKGROUND: Prostate is a moving organ, and its position is also affected by bladder and rectum volumes. Image-guided radiotherapy (IGRT) is being practiced widely for the treatment of prostate carcinoma (Ca). So, it is important to accurately study the effect of bladder and rectum volume changes in treatment. MATERIALS AND METHODS: Thirty patients with Ca prostate were included in this study, and all were treated with 50 Gray (Gy) in 25 fractions for the first phase of treatment. A total of 750 cone-beam computed tomography (CBCT) sessions were performed. Prostate position w.r.t. its day one position was noted, and the bladder and rectum volumes were compared with their volumes on day one. Also, repeat CT was done for five patients after 10 fractions. The initial plan was imported as it was on the repeat CT images, and a hybrid plan was prepared by putting the plan isocenter at the relative anatomical reference point in repeat CT images as it was in primary CT images. The multileaf collimators (MLC) fluence was put as it is, and the dose was calculated using the monitoring units (MU), which were in the initial plan. Doses to bladder, rectum, and the target were analyzed. RESULTS: The mean prostate motion in lateral and anterior-posterior direction was found to be 0.71 (±0.69) centimeter cm) and 0.77 (±0.57) cm, respectively. The mean change in bladder and rectum volumes as compared to that in day one CT images was found to be 110.51 (±84.25) cubic centimeters (cc) and 10.89 (±10.17) cc, respectively. No significant variation was observed in the doses to bladder, rectum, and the target volume in a hybrid plan, as compared to that in actual initial plan. CONCLUSIONS: Bladder and rectum volume affects the position of prostate, rather the dosimetric parameters, and therefore, it can be concluded that daily CBCT should be done for accurate IGRT delivery to the prostate cancer.

A p53-JAK-STAT connection involved in myeloproliferative neoplasm pathogenesis and progression to secondary acute myeloid leukemia.

Since the discovery of JAK2 V617F as a highly prevalent somatic acquired mutation in the majority of myeloproliferative neoplasms (MPNs), it has become clear that these diseases are driven by pathologic activation of JAK2 and eventually of STAT5 and other members of the STAT family. The concept was strengthened by the discovery of the other activating driver mutations in MPL (thrombopoietin receptor, TpoR) and in calreticulin gene, which all lead to persistent activation of wild type JAK2. Although with a rare frequency, MPNs can evolve to secondary acute myeloid leukemia (sAML), a condition that is resistant to treatment. Here we focus on the role of p53 in this transition. In sAML mutations in TP53 or amplification in genes coding for negative regulators of p53 are much more frequent than in de novo AML. We review studies that explore a signaling and biochemical interaction between activated STATs and p53 in MPNs and other cancers. With the development of advanced sequencing efforts, strong evidence has been presented for dominant negative effects of mutated p53 in leukemia. In other studies, gain of function effects have been described that might be cell type specific. A more profound understanding of the potential interaction between p53 and activated STATs is necessary in order to take full advantage of novel p53-targeted therapies.

A prospective observational study to analyse the influence of bladder and rectal volume changes on prostate radiotherapy using IMRT.

AIM: To analyse the interfractional bladder and rectal volume changes and the influence on prostate position. BACKGROUND: Interfractional displacement of prostate due to variation in bladder and rectal volume is usual. It is only rational to study the bladder and rectal volume changes and their effects on prostate position during intensity modulated radiotherapy of prostate cancer. MATERIALS AND METHODS: A prospective study was conducted on twenty patients with localized prostate cancer during the first phase of radiotherapy, where 50 gray in 25 fractions was delivered by the IMRT technique with daily cone beam computed tomography Bladder and rectum volumes were delineated on CBCT images and their volumes were noted. Prostate position was noted on each set of CBCT images with respect to specific reference points defined on the ileum and coccyx, and daily prostate displacement was noted. RESULTS: Mean setup errors in vertical, longitudinal and lateral directions were noted as 1.49, 0.498 and 0.17 cm, respectively. Mean change in bladder and rectal volumes in daily CBCT images with respect to that on the first day CT images was noted as 101.94 and 10.22, respectively. Mean lateral and vertical displacement in prostate position was noted as 0.53 and 0.49 cm respectively. No considerable changes in dosimetric parameters were observed because of bladder and rectal volume changes. CONCLUSIONS: Daily CBCT should be done for accurate treatment delivery by the IMRT technique for prostate radiotherapy as prostate shifts physiologically with changes in rectal and bladder volumes.