Author contributions K.Y. and A.V. performed the majority of experiments and wrote the manuscript. J.Y. assisted with cloning and performed the proximity biotinylation and ubiquitylation experiments. D.E.B. and A.S.W.S. assisted with animal studies. S.G. performed immunofluorescence and analysis of patient PDAC specimens. M.K. assisted with the analysis of flow cytometry data and RNA-seq data. S.M. assisted with immunoblotting and preparing shRNAs. E.Y.L. and S.J.P. cloned fluorescent constructs. K.W.W. and G.E.K. provided PDAC patient specimens and analysis. J.D. provided GFP-NBR1 and GFP-NBR1 dUBA constructs. R.S.B. assisted with transcriptome data analysis. J.D.M. and J.A.P. performed proteomics analysis. D.T.F. provided intellectual feedback and support. R.M.P. and A.C.K. conceived the project, supervised the research, and wrote and edited the paper.Competing interests A.C.K. has financial interests in Vescor Therapeutics, LLC. A.C.K. is an inventor on patents pertaining to KRAS regulated metabolic pathways, redox control pathways in pancreatic cancer, targeting GOT1 as a therapeutic approach, and the autophagic control of iron metabolism. A.

Diffuse-type gastric carcinoma (DGC) is characterized by a highly malignant phenotype with prominent infiltration and stromal induction. We performed whole-exome sequencing on 30 DGC cases and found recurrent RHOA nonsynonymous mutations. With validation sequencing of an additional 57 cases, RHOA mutation was observed in 25.3% (22/87) of DGCs, with mutational hotspots affecting the Tyr42, Arg5 and Gly17 residues in RHOA protein. These positions are highly conserved among RHO family members, and Tyr42 and Arg5 are located outside the guanine nucleotide-binding pocket. Several lines of functional evidence indicated that mutant RHOA works in a gain-of-function manner. Comparison of mutational profiles for the major gastric cancer subtypes showed that RHOA mutations occur specifically in DGCs, the majority of which were histopathologically characterized by the presence of poorly differentiated adenocarcinomas together with more differentiated components in the gastric mucosa. Our findings identify a potential therapeutic target for this poor-prognosis subtype of gastric cancer with no available molecularly targeted drugs.

Millions of people worldwide with incurable end-stage lung disease die because of inadequate treatment options and limited availability of donor organs for lung transplantation 1 . Current bioengineering strategies to regenerate the lung have not been able to replicate its extraordinary cellular diversity and complex three-dimensional arrangement, which are indispensable for life-sustaining gas exchange 2 , 3 . Here we report the successful generation of functional lungs in mice through a conditional blastocyst complementation (CBC) approach that vacates a specific niche in chimeric hosts and allows for initiation of organogenesis by donor mouse pluripotent stem cells (PSCs). We show that wild-type donor PSCs rescued lung formation in genetically defective recipient mouse embryos unable to specify (due to Ctnnb1 cnull mutation) or expand (due to Fgfr2 cnull mutation) early respiratory endodermal progenitors. Rescued neonates survived into adulthood and had lungs functionally indistinguishable from those of wild-type littermates. Efficient chimera formation and lung complementation required newly developed culture conditions that maintained the developmental potential of the donor PSCs and were associated with global DNA hypomethylation and increased H4 histone acetylation. These results pave the way for the development of new strategies for generating lungs in large animals to enable modeling of human lung disease as well as cell-based therapeutic interventions 4 – 6 .

Recent successes in tumor immunotherapies have highlighted the importance of tumor immunity. However, most of the work conducted to date has been on T cell immunity, while the role of B cell immunity in cancer remains more elusive. In this study, immunogenetic repertoire profiling for tumor-infiltrating B and T cells in gastric cancers was carried out to help reveal the architecture of B cell immunity in cancer. Humoral immunity in cancer was shown to involve oligoclonal expansions of tumor-specific and private B cell repertoires. We find that B cell repertoires in cancer are shaped by somatic hypermutation (SHM) either with or without positive selection biases, the latter of which tended to be auto-reactive. Importantly, we identified sulfated glycosaminoglycans (GAGs) as major functional B cell antigens among gastric tumors. Furthermore, natural anti-sulfated GAG antibodies discovered in gastric cancer tissues showed robust growth-suppressive functions against a wide variety of human malignancies of various organs.

BackgroundRecent studies have discovered recurrent RHOA mutations in diffuse-type gastric cancers. These reports show mutant RhoA is an important cancer driver and is a potential therapeutic target. This study aims to investigate the clinicopathological features of diffuse-type gastric cancers with RHOA mutation.MethodsWe performed a thorough review of 87 diffuse-type gastric cancers, including 22 RHOA-mutated and 65 RHOA wild-type gastric cancers.ResultsMost advanced tumors with RHOA mutation appeared as Borrmann type 3 lesions (81 %) developing in the middle (50 %) or distal (32 %) third of the stomach. Histologically, although all of the tumors were predominantly or exclusively composed of poorly cohesive carcinoma, limited tubular differentiation was also observed in 73 % of the RHOA-mutated tumors. Notably, RHOA-mutated tumors more frequently showed a permeative growth pattern at the edge of the mucosal area (59 %) compared with RHOA wild-type tumors (29 %, P = 0.0202). Additionally, the size ratios of the deeply invasive components to the mucosal components were significantly lower in RHOA-mutated tumors [less than 1.45 (median) in 68 % of cases] than in RHOA wild-type tumors (less than 1.45 in 42 % of cases, P = 0.0482). RHOA mutation did not significantly impact survival in this study.ConclusionsThese observations suggest that RHOA mutation may be associated with the growth patterns of diffuse-type gastric cancer but have a limited prognostic impact in isolation. Further studies, including analyses of the other alterations involving the RhoA pathways, such as CLDN18–ARHGAP fusion, as well as functional studies of mutant RhoA, are necessary to clarify the significance of alterations in the RhoA-signaling pathway in diffuse-type gastric cancers.