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Poly-ADP-ribose polymerase (PARP) inhibitors (PARPi) have shown great promise for treating BRCA-deficient tumors. However, over 40% of BRCA-deficient patients fail to respond to PARPi. Here, we report that thioparib, a next-generation PARPi with high affinity against multiple PARPs, including PARP1, PARP2, and PARP7, displays high antitumor activities against PARPi-sensitive and -resistant cells with homologous recombination (HR) deficiency both in vitro and in vivo. Thioparib treatment elicited PARP1-dependent DNA damage and replication stress, causing S-phase arrest and apoptosis. Conversely, thioparib strongly inhibited HR-mediated DNA repair while increasing RAD51 foci formation. Notably, the on-target inhibition of PARP7 by thioparib-activated STING/TBK1-dependent phosphorylation of STAT1, triggered a strong induction of type I interferons (IFNs), and resulted in tumor growth retardation in an immunocompetent mouse model. However, the inhibitory effect of thioparib on tumor growth was more pronounced in PARP1 knockout mice, suggesting that a specific PARP7 inhibitor, rather than a pan inhibitor such as thioparib, would be more relevant for clinical applications. Finally, genome-scale CRISPR screening identified PARP1 and MCRS1 as genes capable of modulating thioparib sensitivity. Taken together, thioparib, a next-generation PARPi acting on both DNA damage response and antitumor immunity, serves as a therapeutic potential for treating hyperactive HR tumors, including those resistant to earlier-generation PARPi.

PARP1 and Chk1 inhibitors have been shown to be synergistic in different cancer models in relatively short time treatment modes. However, the consequences of long-term/repeated treatments with the combinations in cancer models remain unclear. In this study, the synergistic cytotoxicity of their combinations in 8 tumor cell lines was confirmed in a 7-day exposure mode. Then, pancreatic Capan-1 cells were repeatedly treated with the PARP1 inhibitor olaparib, the Chk1 inhibitor rabusertib or their combination for 211-214 days, during which the changes in drug sensitivity were monitored at a 35-day interval. Unexpectedly, among the 3 treatment modes, the combination treatments resulted in the highest-grade resistance to Chk1 (~14.6 fold) and PARP1 (~420.2 fold) inhibitors, respectively. Consistently, G2/M arrest and apoptosis decreased significantly in the resulting resistant variants exposed to olaparib. All 3 resistant variants also unexpectedly obtained enhanced migratory and invasive capabilities. Moreover, the combination treatments resulted in increased migration and invasion than olaparib alone. The expression of 124 genes changed significantly in all the resistant variants. We further demonstrate that activating CXCL3-ERK1/2 signaling might contribute to the enhanced migratory capabilities rather than the acquired drug resistance. Our findings indicate that repeated treatments with the rabusertib/olaparib combination result in increased drug resistance and a more aggressive cell phenotype than those with either single agent, providing new clues for future clinical anticancer tests of PARP1 and Chk1 inhibitor combinations.

Objective To explore a precise method with a microwave antenna for puncture of pulmonary nodules and analyze phenomena that affect the puncture results. Methods Clinical data of 107 cases with solitary malignant pulmonary nodules were collected, and the mean length of pulmonary nodules was 13.6±0.6 mm in CT axial position. A thread-hanging method was used to assist the puncture of pulmonary nodules. The procedure was successful when the needle was not withdrawn and inserted into the central region of the nodule. The success rate and complications of the pulmonary procedure were recorded. The incidence of the following phenomena were also documented: needle coercing, needle slipping, needle tip pushing, pulmonary nodule prolapsing, radial nodule deformation, nodular masking, and radial movement distance of needle tip. Results In all of 107 cases evaluated, the antenna puncture was successful in 101 cases (94.4%) but failed in 6 cases (5.6%). Pneumothorax and pulmonary hemorrhage occurred in 23 (21.5%) and 19 cases (17.8%), respectively. The following phenomena occurred: needle coercing in 9 cases (8.4%), needle slipping in 6 cases (5.6%), needle tip pushing in 19 cases (17.8%), pulmonary nodule prolapsing in 15 cases (14%), radial nodule deformation in 14 cases (13.1%), and nodular masking in 5 cases (4.7%). The mean radial adjusting distance of needle tip was 0.7±0.4 cm. Conclusion The thread-hanging method can assist in the accurate puncture of microwave antenna for pulmonary nodules. We should focus and deal with phenomena that may occur and affect the result of puncture.

Monotherapy with poly ADP-ribose polymerase (PARP) inhibitors results in a limited objective response rate (≤60% in most cases) in patients with homologous recombination repair (HRR)-deficient cancer, which suggests a high rate of resistance in this subset of patients to PARP inhibitors (PARPi). To overcome resistance to PARPi and to broaden their clinical use, we performed high-throughput screening of 99 anticancer drugs in combination with PARPi to identify potential therapeutic combinations. Here, we found that GSK3 inhibitors (GSK3i) exhibited a strong synergistic effect with PARPi in a panel of colorectal cancer (CRC) cell lines with diverse genetic backgrounds. The combination of GSK3β and PARP inhibition causes replication stress and DNA double-strand breaks, resulting in increased anaphase bridges and abnormal spindles. Mechanistically, inhibition or genetic depletion of GSK3β was found to impair the HRR of DNA and reduce the mRNA and protein level of BRCA1. Finally, we demonstrated that inhibition or depletion of GSK3β could enhance the in vivo sensitivity to simmiparib without toxicity. Our results provide a mechanistic understanding of the combination of PARP and GSK3 inhibition, and support the clinical development of this combination therapy for CRC patients.

Several poly(ADP ribose) polymerase (PARP) inhibitors (PARPi) have been approved for cancer therapy; however, intrinsic and acquired resistance has limited their efficacy in the clinic. In fact, cancer cells have developed multiple mechanisms to overcome PARPi cytotoxicity in even a single cancer cell. In this study, we generated three PARPi-resistant BRCA2-deficient pancreatic Capan-1 variant cells using olaparib (Capan-1/OP), talazoparib (Capan-1/TP), and simmiparib (Capan-1/SP). We identified novel mutations in intron 11 of BRCA2, which resulted in the expression of truncated BRCA2 splice isoforms. Functional studies revealed that only a fraction (32-49%) of PARPi sensitivity could be rescued by depletion of BRCA2 isoforms. In addition, the apoptosis signals (phosphatidylserine eversion, caspase 3/7/8/9 activation, and mitochondrial membrane potential loss) were almost completely abrogated in all PARPi-resistant variants. Consistently, overexpression of the anti-apoptotic proteins cyclooxygenase 2 (COX-2) and baculoviral IAP repeat-containing 3 (BIRC3) occurred in these variants. Depletion of COX-2 or BIRC3 significantly reduced apoptotic resistance in the PARPi-resistant sublines and reversed PARPi resistance by up to 70-72%. Furthermore, exogenous addition of prostaglandin E2, a major metabolic product of COX-2, inhibited PARPi-induced apoptotic signals; however, when combined with the BIRC3 inhibitor LCL161, there was significantly enhanced sensitivity of the resistant variants to PARPi. Finally, PARPi treatment or PARP1 depletion led to a marked increase in the mRNA and protein levels of COX-2 and BIRC3, indicating that PARP1 is a negative transcriptional regulator of these proteins. Together, our findings demonstrated that during the chronic treatment of cells with a PARPi, both BRCA2 intron 11 mutations and COX-2/BIRC3-mediated apoptotic resistance led to PARPi resistance in pancreatic Capan-1 cells.

Objective To investigate the characteristics of gut microbiome and their associations with lymphocyte subsets and disease activity in patients with ankylosing spondylitis (AS). Methods This study was a retrospective analysis. The subjects of the study were AS patients who were hospitalized in the Second Hospital of Shanxi Medical University from December 2019 to June 2020, as well as gender- and age-matched healthy controls (HCs). The fecal samples were collected, and the V3-V4 variable regions of 16S rRNA gene of gut microbiome were sequenced for bioinformatics analysis. Peripheral venous blood was collected from AS patients to determine peripheral blood lymphocyte subsets and disease activity indicators. Spearman correlation test was used to analyze the correlations between the relative abundances of gut microbiota and peripheral blood lymphocyte subsets as well as disease activity in AS patients. Results A total of 62 AS patients (11 with low disease activity, 26 with high disease activity, and 25 with extremely high disease activity) and 62 healthy people who met the inclusion and exclusion criteria were enrolled. As for α-diversity, ACE and Chao1 indices were lower in AS than in HCs(P < 0.05). Bray curtis distance-based β-diversity analysis revealed significant difference in the microbial community between AS and HCs (P < 0.01). As for the composition of the gut microbiome, Firmicutes, Bacteroidetes, and Proteobacteria were the dominant phyla in the gut microbiota of both groups, but there were differences in the abundance of various bacteria at the phylum and genus levels. In Stamp analysis, fecal microbial communities in AS differed significantly from those in HCs, which were characterized by higher abundances of phylum Proteobacteria and Patescibacteria(all P < 0.05) and a lower abundance of phylum Firmicutes and Fusobacteriota (all P < 0.05). At the genus level, the abundances of Escherichia-Shigella, Klebsiella and Enterococcus were increased while those of Prevotella and Faecalibacterium were decreased in AS patients compared to HCs(all P < 0.05). Spearman correlation analysis showed that the relative abundances of Faecalibacterium, Ruminococcus and Klebsiella in AS patients were significantly positively correlated with disease activity or its related indicators(all P < 0.05). There were positive correlations between Agathobacter and T cell (r=0.302, P=0.017), CD4+T cell (r=0.310, P=0.014), B cell (r=0.292, P=0.021), Th2 cell (r=0.429, P < 0.001), Th17 cell (r=0.288, P=0.023), Streptococcus and B cell (r=0.270, P=0.034), Prevotella and Th1 cell (r=0.279, P=0.028), Th17 cell (r=0.262, P=0.040), CAG-352 and Th1 cell (r=0.283, P=0.030). There were negative correlations between Escherichia-Shigella and Th2 cell(r=-0.261, P=0.040), other Enterobacteriaceae and CD4+T cell (r=-0.255, P=0.046). Conclusions The diversity of gut microbiota is reduced in AS patients. The abundance of pathogenic bacteria in AS patients is increased, which is correlated with changes in peripheral blood lymphocyte subsets and disease activity. Dysbiosis may be involved in the occurrence and development of AS.

Response surface methodology was used to determine the optimum ratio of rice husk dietary fiber, soybean hull dietary fiber, and inulin as 1.40, 1.42, and 3.24%. The effects of compound and single dietary fiber on water holding capacity, gel strength, secondary structure, rheological properties, chemical action force, and microstructure of myofibrillar proteins (MP) gel were investigated. The application of composite dietary fiber significantly (P < 0.05) improved the gel strength, water holding capacity and storage modulus (G′) of MP gel. Fourier transform infrared spectrum analysis shows that the addition of compound dietary fiber can make the gel structure more stable. The effect of dietary fiber complex on the chemical action of MP gel was further studied, and it was found that hydrophobic interaction and disulfide bond could promote the formation of compound gel. By comparing the microstructure of the MP gel with and without dietary fiber, the results showed that the MP gel with compound dietary fiber had smaller pores and stronger structure. Therefore, the rice hull dietary fiber, the soybean hull dietary fiber and the inulin are compounded and added into the low-fat recombinant meat product in a proper proportion, so that the quality characteristics and the nutritional value of the low-fat recombinant meat product can be effectively improved, the rice hull dietary fiber has the potential of being used as a fat substitute, and a theoretical basis is provided for the development of the functional meat product.