The efficacy and safety of Bruton tyrosine kinase inhibitors as monotherapy in the treatment of newly diagnosed patients with Waldenström macroglobulinemia / 中华血液学杂志

Objective: To investigate the efficacy and safety of Bruton tyrosine kinase inhibitors (BTKi) ibrutinib or zanubrutinib monotherapy in newly diagnosed patients with Waldenström macroglobulinemia (WM) . Methods: The efficacy and adverse effects of 58 patients with newly diagnosed WM receiving BTKi monotherapy in Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine were analyzed retrospectively from January 2018 to August 2022. Results: The response of 55 patients may be examined. Forty patients received ibrutinib monotherapy for a median of 15 months, with an overall response rate (ORR) of 85%, a main remission rate (MRR) of 70%, and a very good partial remission (VGPR) rate of 10%. Fifteen patients received zanubrutinib monotherapy for a median of 13 months, with an ORR of 93%, an MRR of 73%, and a VGPR rate of 0%. For various reasons, 10 patients were converted from ibrutinib to zanubrutinib. Ibrutinib treatment lasted an average of 7.5 months before conversion. The median duration of zanubrutinib therapy after conversion was 3.5 months. The ORRs before and after conversion were 90% and 100%, MRRs were 80% and 80%, and VGPR rates were 10% and 50%, respectively. After a median of 16 months, the 24-month progression-free survival (PFS) rate of patients who received both BTKi was 86%. PFS did not differ statistically across individuals with low, medium, and high-risk ISS scores (P=0.998). All of the patients survived. The most common side effects of BTKi were neutropenia and thrombocytopenia, which occurred in 12% and 10% of all patients, respectively. Ibrutinib accounts for 5% of atrial fibrillation, and zanubrutinib has a 7% risk of bleeding. Conclusions: In treating WM, ibrutinib or zanubrutinib provides good efficacy and tolerable adverse effects.

Isolation of a novel disintegrin containing Arg-Gly-Asp tripeptide sequence from Gloydius brevicaudus venom and investigation of its biological activities / 药学学报

Snake venom has special pharmacological activities and contains a array of small polypeptides that can antagonize integrins, therefore called disintegrins. Disintegrins can block integrin-dependent platelet aggregation, tumor growth, and tumor metastasis. A disintegrin fraction was isolated and purified from the venom of snake Gloydius brevicaudus (GBV). Its physical and chemical properties were characterized, and its biological activities were investigated. The crude venom of GBV were isolated by Superdex 75 gel filtration chromatography. The anti-platelet aggregation activity of the fractions was screened by the Born method. The fraction that shown anti-platelet activity was further purified with Sephadex G-25 gel filtration, DEAE Sepharose Fast Flow ion exchange chromatography, and Lichrospher C18 reversed-phase chromatography respectively. The purity of the active component was analyzed with SDS-PAGE (Tris-Tricine system) and high-performance liquid-phase chromatography (HPLC), with protein concentration determined by the Bradford method. The molecular weight was evaluated by the gel imaging method and mass spectrometry, and the isoelectric point was measured by disc isoelectric focusing electrophoresis. The protease activity was measured with the Rick method. The phospholipase A activity was determined by the automatic potentiometric titration method. Amino acid sequencing results were subjected to homology comparison using the BLAST program. Seven fractions (Ⅰ-Ⅶ) were isolated from GBV by gel filtration chromatography on Superdex 75 column. The fraction Ⅳ inhibited the platelet aggregation induced by ADP with molecular weight lower than 10 000 Da, suggesting a disintegrin component. A disintegrin named GBV-Ⅳ4 was purified from the fraction by Sephadex G-25 gel filtration, DEAE Sepharose Fast Flow ion-exchange and Lichrospher C18 reverse chromatography. It was homogeneous shown as a single band on SDS-polyacrylmide gel electrophoresis (SDS-PAGE, Tris-Tricine system) with molecular weight 8 746 Da as calculated by Image Master VDS system. The isoelectric point of GBV-Ⅳ4 was 6.3 by disc polyacrylamide gel electrophoresis. GBV-Ⅳ4 exhibited no detectable phospholipase A2 (PLA2) activity with the pH-stat technique or proteinase activity according to the method of Rick. GBV-Ⅳ4 is composed of 70 amino acids with RGD (Arg-Gly-Asp) active region and a molecular weight of 7 442 Dalton as assayed by Mass Spectrography. Characterization of GBV-Ⅳ4 is consistent with meta-chain disintegrin (70 amino acid sequence, six pairs of disulfide bond). Retrieved by Genbank, GBV-Ⅳ4 has high homology with other disintegrins. We concluded that GBV-Ⅳ4 is a novel disintegrin contained RGD. GBV-Ⅳ4 showed dose-dependent inhibition of ADP- or thrombin-induced platelet aggregation with IC50 0.339 or 0.577 μg·mL-1 respectively. In conclusion, a new disintegrin derived from the GBV snake venom and named GBV-Ⅳ4 containing RGD tripeptide sequence could inhibit platelet aggregation.

Phenylhexyl isothiocyanate induces gene p15 demethylation by down-regulating DNA methyltransferases in Molt-4 cells / 药学学报

This study is to investigate the effect of phenylhexyl isothiocyanate (PHI), which has been proved to be a novel histone deacetylase inhibitor (HDACi) recently, on gene p15 de novo expression in acute leukemia cell line Molt-4, and to further study its potential mechanism. Modified methylation specific PCR (MSP) was used to screen p15-M and p15-U mRNA. DNA methyltransferasel (DNMT1), 3A (DNMT3A), 3B (DNMT3B) and p15 mRNA were measured by RT-PCR. P15 protein was detected by Western blotting. Hypermethylation of gene p15 was reversed and activation transcription of gene p15 in Molt-4 was de novo after 5 days exposure to PHI in a concentration dependent manner. DNMT1 and DNMT3B were inhibited by exposure to PHI for 5 days (P < 0.05). Alteration of DNMT3A was not significant. It is showed that PHI could reverse hypermethylation of gene p15 and transcriptional activation of gene p15 is de novo by PHI. It may result from down-regulating DNA methyltransferases, DNMT1 and DNMT3B, or up-regulating the histone acetylation that allows chromatin unfolding and the accessibility of regulators for transcriptional activation in the p15 promoter.