Site-Specifically Modified Peptide Inhibitors of Protein Tyrosine Phosphatase 1B and T-Cell Protein Tyrosine Phosphatase with Enhanced Stability and Improved In Vivo Long-Acting Activity.

Protein tyrosine phosphatase 1B (PTP1B) and TC-PTP can function in a coordinated manner to regulate diverse biological processes including insulin and leptin signaling, T-cell activation, and tumor antigen presentation, which makes them potential targets for several therapeutic applications. We have previously demonstrated that the lipidated BimBH3 peptide analogues were a new class of promising PTP1B inhibitors with once-weekly antidiabetic potency. Herein, we chemically synthesized two series of BimBH3 analogues via site-specific modification and studied their structure-activity relationship. The screened analogues S2, S6, A2-14, A2-17, A2-20, and A2-21 exhibited an improved PTP1B/TC-PTP dual inhibitory activity and achieved good stability in the plasma of mice and dogs, which indicated long-acting potential. In mouse models of type 2 diabetes mellitus (T2DM), the selected analogues S6, S7, A2-20, and A2-21 with an excellent target activity and plasma stability generated once-weekly therapeutic potency for T2DM at lower dosage (0.5 µmol/kg). In addition, evidence was provided to confirm the cell permeability and targeted enrichment of the BimBH3 analogues. In summary, we report here that site-specific modification and long fatty acid conjugation afforded cell-permeable peptidomimetic analogues of BimBH3 with enhanced stability, in vivo activity, and long-acting pharmacokinetic profile. Our findings could guide the further optimization of BimBH3 analogues and provide a proof-of-concept for PTP1B/TC-PTP targeting as a new therapeutic approach for T2DM, which may facilitate the discovery and development of alternative once-weekly anti-T2DM drug candidates.

Methylation of Septin9, SRSF1, and PAX8 in Early Screening of Colorectal Cancer in the Population Undergoing Physical Examinations.

BACKGROUND: The aim was to investigate the value of blood Septin9, SRSF1, and PAX8 gene methylation detection techniques in early screening of colorectal cancer (CRC). METHODS: A prospective cohort study enrolled 3,000 participants undergoing routine physical examination at Shizong County People's Hospital Health Management Center from December 2021 through November 2022, including 1,512 males and 1,488 females, ranging in age from 20 to 90 years, with a median age of 49 years. Fresh blood samples were collected and tested for Septin9, SRSF1, and PAX8 gene methylation. Positive or negative results were reported. Colonoscopy was recommended for positive results and telephone follow-up for negative results. A chi-squared test analyzed the positive rate of initial screening, colonoscopy compliance, and the detection rate of colorectal lesions. Finally, combined with the follow-up data, the screening effect of Septin9, SRSF1, and PAX8 methylation detection on CRC was evaluated. RESULTS: Among 3,000 cases, 215 cases were preliminarily positive, with a positive rate of 7.1% (215/3,000). The positive rate of Septin9 gene methylation was the highest (6%, 180/3000), followed by SRSF1 (4.1%, 124/3000) and PAX8 (3.6%, 108/3000). The sensitivity of combined detection of Septin9, SRSF1, and PAX8 methylation in the diagnosis of CRC was higher than that of the three alone, and the specificity, positive predictive value, and negative predictive value of combined detection were higher than that of the single detection of blood Septin9, SRSF1, and PAX8 DNA methylation. In addition, the positive rate of initial screening increased with age (χ2 = 32.135, p < 0.001). A total of 150 cases underwent further colonoscopy, and the colonoscopy compliance rate was 69.8% (150/215). Among 150 cases who completed colonoscopy, 5 cases of CRC (3.4%), 25 cases of advanced adenoma (16.0%), 78 cases of non-advanced adenoma (52.0%), and 24 cases of non-adenomatous polyps (22.7%) were detected. The positive predictive value of Septin9, SRSF1, and PAX8 methylation was 94% (141/150) for all colorectal lesions, and 70.0% (105/150) for colorectal cancer and precancerous lesions. CONCLUSIONS: Blood Septin9, SRSF1, and PAX8 gene methylation detection, combined with colonoscopy, can effectively detect colorectal cancer and precancerous lesions. This strategy may be an effective way to carry out large-scale colorectal cancer screening in the general risk population. Combined detection of the three genes can improve the detection rate of colorectal cancer, but Septin9 methylation is the most sensitive, which can be used for screening and efficacy evaluation of CRC.

Discovery of Novel PTP1B Inhibitors with Once-Weekly Therapeutic Potential for Type 2 Diabetes: Design, Synthesis, and In Vitro and In Vivo Investigations of BimBH3 Peptide Analogues.

Poor medication adherence in patients with type 2 diabetes mellitus has become one of the main causes of suboptimal glycemic control. Once-weekly drugs can markedly improve the convenience, adherence, and quality of life of T2DM patients; thus, they are clinically needed and preferred. PTP1B plays a negative role in both insulin and leptin signaling pathways, which makes it an important target for diabetes. Herein, we design and synthesize 35 analogues of core BimBH3 peptide via lipidation/acylation strategy based on our previous work and evaluate their PTP1B inhibitory activity, obtaining the primary structure-activity relationship. Five compounds with good PPT1B inhibitory activity, target selectivity, and significantly improved stability were selected for molecular docking study and searching candidate molecules with long-acting antidiabetic potential. The in vivo anti-T2DM evaluation validated the once-weekly therapeutic potential of analogues 19, 26, 27, 31, and 33, which were comparable with semaglutide and therefore presented as promising drug candidates.