A structure-based virtual screening identifies a novel MDM2 antagonist in the activation of the p53 signaling and inhibition of tumor growth.

p53, a tumor suppressor protein, has a vital role in the regulation of the cell cycle, apoptosis, and DNA damage repair. The degradation of p53 is predominantly controlled by the murine double minute 2 (MDM2) protein, a ubiquitin E3 ligase. The overexpression or amplification of MDM2 is commonly observed in various human cancers bearing wild-type p53 alleles, leading to the rapid degradation of the p53 protein and the attenuation of p53 tumor suppression functions. Thus, a major effort in p53-based cancer therapy has been to research MDM2 antagonists that specifically stabilize and activate p53, leading to the suppression of tumor growth. However, despite numerous efforts to develop MDM2 antagonists, to date they have failed to reach clinical use, largely because of the cytotoxicity associated with these small molecules. This study used our newly designed structure-based virtual screening approach on a commercial compound library to identify a novel compound, CGMA-Q18, which directly binds to MDM2, leading to the activation of p53, the induction of apoptosis, and cell cycle arrest in cancer cells. Notably, CGMA-Q18 significantly inhibited tumor xenograft growth in nude mice without observable toxicity. These findings highlight our useful virtual screening protocol and CGMA-Q18 as a putative MDM2 antagonist.

Chinese medicine for outcomes in colorectal cancer patients: A retrospective clinical study / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of Chinese medicine (CM) on survival of patients with stage II and III colorectal cancer (CRC).</p><p><b>METHODS</b>A total of 295 patients who received chemotherapy were assigned to Group 1. The other 171 patients received the same chemotherapy treatment combined with the usage of CM Jianpi Jiedu Formula (, JPJD) for more than 3 months (Group 2). Patients' survival time, relapse and metastasis, and cause of death were observed. Cox proportional hazard regression models were established for the analysis of the effect of independent factors on the survival prognosis of patients with CRC.</p><p><b>RESULTS</b>The survival rate of patients in Group 2 was higher than that of Group 1 (P<0.05). Compared with Group 1, the mean survival time was prolonged by 5.594 months and the median survival time was prolonged by 6 months in Group 2 (P=0.004). Cox regression analysis indicated that CM combined with chemotherapy provided signifificant protective effect, as observed with the improvements in the survival rates of CRC patients (P<0.01).</p><p><b>CONCLUSION</b>CM can improve the survival rate in patients with stage II and III CRC.</p>