JEWJITSU PEPTIDES Research Roundup: TGF-β receptor–targeting peptides, a 13C breath test for gut transit, and neoantigen strategies in CRC

An exploratory in vitro study evaluated novel peptides designed from receptor–ligand interface sequences to target the TGF‑β receptor I/II complex. The authors tested peptides labeled 2_5 and 2_6 in HEK293T cells at 20 and 50 μM, using the TGF‑β receptor I inhibitor SD‑208 as a reference. Outcomes were measured by Western blot and densitometry for total and phosphorylated SMAD2, SMAD3, ERK1/2 and JNK. The report describes peptide 2_5 as having the strongest activity among the candidates, with marked reductions reported for ERK1/2 measures and a reduction in total SMAD2 at 50 μM, while peptide 2_6 showed minimal effects.

The breath‑test methods paper describes a noninvasive approach to measure oral–cecal transit time (OCTT) in mice based on 13C‑labeled mannitol. The study reports that murine cecal microbiota metabolize the tracer to produce measurable 13CO2 in exhaled breath, and combines indirect calorimetry with real‑time 13C/12C ratio measurement to track transit in unrestrained, freely moving animals. The authors position the assay as a high‑throughput, longitudinal alternative to invasive or terminal OCTT methods and illustrate its use in the context of semaglutide treatment–associated delayed transit in mice.

A review focused on colorectal cancer (CRC) summarizes mechanisms that generate tumor neoantigens, including frameshifts, single‑nucleotide variants, alternative RNA splicing and circular RNA–derived epitopes, and outlines how neoantigens are processed and presented via MHC for recognition by CD8+ and CD4+ T cells. The review examines personalized neoantigen vaccine platforms (peptide, RNA, dendritic cell), adoptive T‑cell approaches (TIL, CAR‑T, TCR‑T), and discusses barriers such as low tumor mutational burden, adaptive immune evasion and spatial heterogeneity. It also notes emerging preclinical strategies like engineered delivery systems and pharmacologic induction of neoantigen presentation as areas for further development.