Retrospective efficacy analysis of olaparib combined with bevacizumab in the treatment of advanced colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is a highly prevalent malignancy of the digestive tract worldwide, characterized by a significant morbidity and mortality rate and subtle initial symptoms. Diarrhea, local abdominal pain, and hematochezia occur with the development of cancer, while systemic symptoms such as anemia and weight loss occur in patients with advanced CRC. Without timely interventions, the disease can have fatal consequences within a short span. The current therapeutic options for colon cancer include olaparib and bevacizumab, which are widely utilized. This study intends to evaluate the clinical efficacy of olaparib combined with bevacizumab in the treatment of advanced CRC, hoping to provide insights into advanced CRC treatment. AIM: To investigate the retrospective efficacy of olaparib combined with bevacizumab in the treatment of advanced CRC. METHODS: A retrospective analysis was conducted on a cohort of 82 patients with advanced colon cancer who were admitted to the First Affiliated Hospital of the University of South China between January 2018 and October 2019. Among them, 43 patients subjected to the classical FOLFOX chemotherapy regimen were selected as the control group, and 39 patients undergoing treatment with olaparib combined with bevacizumab were selected as the observation group. Subsequent to different treatment regimens, the short-term efficacy, time to progression (TTP), and incidence rate of adverse reactions between the two groups were compared. Changes in serum-related indicators [vascular endothelial growth factor (VEGF), matrix metalloprotein-9 (MMP-9), cyclooxygenase-2 (COX-2)] and tumor markers [human epididymis protein 4 (HE4), carbohydrate antigen 125 (CA125), carbohydrate antigen 199 (CA199)] levels before and after treatment were compared between the two groups at the same time. RESULTS: The objective response rate was discovered to be 82.05%, and the disease control rate was 97.44% in the observation group, which were significantly higher than the respective rates of 58.14% and 83.72% in the control group (P < 0.05). The median TTP was 24 mo (95%CI: 19.987-28.005) in the control group and 37 mo (95%CI: 30.854-43.870) in the observation group. The TTP in the observation group was significantly better than that in the control group, and the difference held statistical significance (log-rank test value = 5.009, P = 0.025). Before treatment, no substantial difference was detected in serum VEGF, MMP-9, and COX-2 levels and tumor markers HE4, CA125, and CA199 levels between the two groups (P > 0.05). Following treatment with different regimens, the above indicators in the two groups were remarkably promoted (P < 0.05), VEGF, MMP-9, and COX-2 in the observation group were lower than those in the control group (P < 0.05), and HE4, CA125, and CA199 levels were also lower than those in the control group (P < 0.05). Vis-à-vis the control group, the total incidence of gastrointestinal reactions, thrombosis, bone marrow suppression, liver and kidney function injury, and other adverse reactions in the observation group was notably lowered, with the difference considered statistically significant (P < 0.05). CONCLUSION: Olaparib combined with bevacizumab in the treatment of advanced CRC demonstrates a strong clinical effect of delaying disease progression and reducing the serum levels of VEGF, MMP-9, COX-2 and tumor markers HE4, CA125 and CA199. Moreover, given its fewer adverse reactions, it can be regarded as a safe and reliable treatment option.

Improved Insulating Properties of Polymer Dielectric by Constructing Interfacial Composite Coatings.

Polymeric dielectrics exhibit remarkable dielectric characteristics and wide applicability, rendering them extensively employed within the domain of electrical insulation. Nevertheless, the electrical strength has always been a bottleneck, preventing its further utilization. Nanocomposite materials can effectively improve insulation strength, but uniform doping of nanofillers in engineering applications is a challenge. Consequently, a nanocomposite interfacial coating was meticulously designed to interpose between the electrode and the polymer, which can significantly improve DC breakdown performance. Subsequently, the effects of filler concentration and coating duration on DC breakdown performance, high field conductivity, and trap distribution characteristics were analyzed. The results indicate that the composite coating introduces deep traps between the electrode-polymer interface, which enhances the carrier confinement, resulting in reduced conductivity and enhanced DC breakdown strength. The incorporation of a composite coating at the interface between the electrode and polymer presents novel avenues for enhancing the dielectric insulation of polymers.

Evaluation of a flavonoid library for inhibition of interaction of HIV-1 integrase with human LEDGF/p75 towards a structure-activity relationship.

Background: Proteinsprotein interaction (PPI) between lens epithelium-derived growth factor (LEDGF/p75) and human immunodeficiency virus (HIV) integrase (IN) becomes an attractive target for anti-HIV drug development.Methods: The blockade of this interaction by small molecules could potentially inhibit HIV-1 replication. In this study, a panel of 99 structurally related flavonoids were was tested, concerning their ability to inhibit IN-LEDGF/p75 interaction, using a homogeneous time time-resolved fluorescence (HTRF) assay. Results: From the obtained results, it was possible to observe that the flavonoid with hydroxyl group in C3-, C4-, C5- and C7-position on the A-ring, C4'- and C5'-position of the B-ring, a carbonyl group of the C-ring, was more active against IN-LEDGF/p75 interaction, through competitive inhibition. Moreover, the binding modes of representative compounds, including myricetin, luteolin, dihydrorobinetin, naringenin, epicatechin, genistein and helichrysetin, were analyzedanalysed by molecular docking. Biolayer interferometry assay confirmed that these representative compounds disrupted the PPI by binding to IN with KD values ranging from 1.0 to 3.6 µM.Conclusion: This study presents the first to quantitative comparation of the effect of flavonoids with different structural subclasses on IN-LEDGF/p75 interaction. Our findings provide new insights into the development of inhibitors targeting IN-LEDGF/p75 interaction using flavonoids. Key MessagesHIV-1 integrase (IN)-LEDGF/p75 interaction is an attractive target for antiviral drug development.For the first time, the structure-activity relationship of flavonoids belonging to seven flavonoidic subclasses on IN-LEDGF/p75 interaction was determined.This study comprehends an HTRF-based screening system, biolayer interferometry and an in silico molecular docking analysis.

Effect of rs67085638 in long non-coding RNA (CCAT1) on colon cancer chemoresistance to paclitaxel through modulating the microRNA-24-3p and FSCN1.

It has been reported that rs67085638 in long non-coding RNAs (lncRNA)-CCAT1 was associated with the risk of tumorigenesis. Also, CCAT1 could affect chemoresistance of cancer cells to paclitaxel (PTX) via regulating miR-24-3p and FSCN1 expression. In this study, we aimed to investigate the effect of rs67085638 on the expression of CCAT1/miR-24-3p/FSCN1 and the response of colon cancer to the treatment of PTX. 48 colon cancer patients were recruited and grouped by their genotypes of rs67085638 polymorphism as a CC group (N = 28) and a CT group (N = 20). PCR analysis, IHC assay and Western blot, TUNEL assay and flow cytometry were conducted. LncRNA-CCAT1 and FSCN1 mRNA/protein were overexpressed, whereas miR-24-3p was down-regulated in the CT-genotyped patients and cells compared with those in the CC-genotyped patients and cells. The survival of colon cancer cells was decreased, whereas the apoptosis of colon cancer cells was increased by PTX treatment in a dose-dependent manner. MiR-24-3p was validated to target lncRNA-CCAT1 and FSCN1 mRNA, and the overexpression of CCAT1 could reduce the expression of miR-24-3p although elevating the expression of FSCN1. Knockdown of lncRNA-CCAT1 partly reversed the suppressed growth of CT-genotyped tumours. And the knockdown of lncRNA-CCAT1 partly reversed the dysregulation of lncRNA-CCAT1 and FSCN1 mRNA/protein in rs67085638-CT + NC shRNA mice. The findings of this study demonstrated that the presence of the minor allele of rs67085638 increased the expression of CCAT1 and accordingly enhanced the resistance to PTX. Down-regulation of CCAT1 significantly re-stored the sensitivity to PTX of colon cancer cells.

The selenium-containing drug ebselen potently disrupts LEDGF/p75-HIV-1 integrase interaction by targeting LEDGF/p75.

Lens-epithelium-derived growth-factor (LEDGF/p75)-binding site on HIV-1 integrase (IN), is an attractive target for antiviral chemotherapy. Small-molecule compounds binding to this site are referred as LEDGF-IN inhibitors (LEDGINs). In this study, compound libraries were screened to identify new inhibitors of LEDGF/p75-IN interaction. Ebselen (2-phenyl-1,2-benzisoselenazol-3-one), a reported anti-HIV-1 agent, was identified as a moderate micromolar inhibitor of LEDGF/p75-IN interaction. Ebselen inhibited the interaction by binding to LEDGF/p75 and the ability of ebselen to inhibit the interaction could be reversed by dithiothreitol (DTT). BLI experiment showed that ebselen probably formed selenium-sulphur bonds with reduced thiols in LEDGF/p75. To the best of our knowledge, we showed for the first time that small-molecule compound, ebselen inhibited LEDGF/p75-IN interaction by directly binding to LEDGF/p75. The compound discovered here could be used as probe compounds to design and develop new disrupter of LEDGF/p75-IN interaction.

Fragmentation characteristics of hydroxycinnamic acids in ESI-MSn by density functional theory.

This work aims to analyze the electrospray ionization multistage mass spectrometry (ESI-MSn ) fragmentation characteristics of hydroxycinnamic acids (HCAs) in negative ion mode. The geometric parameters, energies, natural bond orbitals and frontier orbitals of fragments were calculated by density functional theory (DFT) to investigate mass spectral fragmentation mechanisms. The results showed that proton transfer always occurred during fragmentation of HCAs; their quasi-molecular ions ([M - H]- ) existed in more than one form and were mainly with the lowest energy. The fragmentation characteristics included the followings: (1) according to the different substitution position of phenolic hydroxyl group, the ring contraction reaction by CO elimination from benzene was in an increasingly difficult order: m-phenolic hydroxyl > p-phenolic hydroxyl > o-phenolic hydroxyl; and (2) ortho effect always occurred in o-dihydroxycinnamic acids (o-diHCAs), i.e. one phenolic hydroxyl group offered H+ , which combined with the other one to lose H2 O. In addition, there was a nucleophilic reaction during ring contraction in diHCAs that oxygen atom attacked the carbon atom binding with the other phenolic hydroxyl to lose CO2 . The fragmentation characteristics and mechanism of HCAs could be used for analysis and identification of such compounds quickly and effectively, and as reference for structural analogues by ESI-MS. Copyright © 2017 John Wiley & Sons, Ltd.