Yin, Ning

Abstract Lung adenocarcinoma (LUAD), the most prevalent subtype of lung cancer, can arise from two different cell populations: alveolar type 2 (AT2) cells and bronchiolar club cells. By utilizing genomic data from the cancer genome atlas program, human LUAD cell lines, and the well-characterized LSL-KrasG12D/Trp53-/- (KP) mouse model, we demonstrated that tumors arising from club cells are much more aggressive and follow a different trajectory of tumorigenesis when compared to those arising from AT2 cells. Intriguingly, our data strongly suggest that expression and signaling activity of protein kinase C iota (PKCι) can profoundly affect the cell of origin and oncogenic signaling pathways employed by resultant tumors. Specifically, KP-mediated transformation of club cells appears to be dependent on PKCι-ELF3-NOTCH3 and PKCι-YAP1 signaling axes, while AT2 cell malignancy is dependent on the PKCι-independent WNT signaling. In addition, club-cell-origin tumors exhibit an enrichment of cancer stem cells and increased infiltration of immunosuppressive myeloid cells in comparison to AT2-cell-origin tumors. This results in accelerated progression and increased likelihood of metastasis by LUAD tumors that originate from club cells. Taken together, our results indicate that PKCι expression and signaling activity can profoundly influence the cells of origin, tumor trajectories, and therapeutic vulnerabilities of LUAD tumors. Citation Format: Duy T. Nguyen, Ning Yin, Capella R. Weems, Lee Jamieson, Kayleah Meneses, Yi Liu, Nicole R. Murray, Alan P. Fields. A lineage-specific role of oncogenic protein kinase Cι in lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4299.

Lung adenocarcinoma (LUAD) is the most prevalent form of non–small cell lung cancer (NSCLC) and a leading cause of cancer death. Immune checkpoint inhibitors (ICIs) of programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) signaling induce tumor regressions in a subset of LUAD, but many LUAD tumors exhibit resistance to ICI therapy. Here, we identified Prkci as a major determinant of response to ICI in a syngeneic mouse model of oncogenic mutant Kras / Trp53 loss (KP)–driven LUAD. Protein kinase Cι (PKCι)–dependent KP tumors exhibited resistance to anti–PD-1 antibody therapy (α-PD-1), whereas KP tumors in which Prkci was genetically deleted (KPI tumors) were highly responsive. Prkci- dependent resistance to α-PD-1 was characterized by enhanced infiltration of myeloid-derived suppressor cells (MDSCs) and decreased infiltration of CD8 + T cells in response to α-PD-1. Mechanistically, Prkci regulated YAP1-dependent expression of Cxcl5 , which served to attract MDSCs to KP tumors. The PKCι inhibitor auranofin inhibited KP tumor growth and sensitized these tumors to α-PD-1, whereas expression of either Prkci or its downstream effector Cxcl5 in KPI tumors induced intratumoral infiltration of MDSCs and resistance to α-PD-1. PRKCI expression in tumors of patients with LUAD correlated with genomic signatures indicative of high YAP1-mediated transcription, elevated MDSC infiltration and low CD8 + T cell infiltration, and with elevated CXCL5 / 6 expression. Last, PKCι-YAP1 signaling was a biomarker associated with poor response to ICI in patients with LUAD. Our data indicate that immunosuppressive PKCι-YAP1-CXCL5 signaling is a key determinant of response to ICI, and pharmacologic inhibition of PKCι may improve therapeutic response to ICI in patients with LUAD.

A gradual loss of dopamine-producing nerve cells gives rise to a common neurodegenerative Parkinson’s disease (PD). This disease causes a neurotransmitter imbalance in the brain and initiates a cascade of complications in the rest of the body that appears as distressing symptoms which include gait problems, tremor, gastrointestinal (GI) disorders and cognitive decline. To aid dopamine deficiency, treatment in PD patients includes oral medications, in addition to other methods such as deep brain stimulation and surgical lesioning. Scientists are extensively studying molecular and signaling mechanisms, particularly those involving phenotypic transcription factors and their co-regulatory proteins that are associated with neuronal stem cell (SC) fate determination, maintenance and disease state, and their role in the pathogenesis of PD. Advancement in scientific research and “personalized medicine” to augment current therapeutic intervention and minimize the side effects of chemotherapy may lead to the development of more effective therapeutic strategies in the near future. This review focuses on PD and associated GI complications and summarizes the current therapeutic modalities that include stem cell studies and combinatorial drug treatment.