Cancer cell-intrinsic expression of MHC II in lung cancer cell lines is actively restricted by MEK/ERK signaling and epigenetic mechanisms.

Background: Programmed death 1/programmed death ligand 1 (PD-1/PD-L1) targeted immunotherapy affords clinical benefit in ~20% of unselected patients with lung cancer. The factor(s) that determine whether a tumor responds or fails to respond to immunotherapy remains an active area of investigation. We have previously defined divergent responsiveness of two KRAS-mutant cell lines to PD-1/PD-L1 blockade using an orthotopic, immunocompetent mouse model.

Cancer Cell-Intrinsic Expression of MHC Class II Regulates the Immune Microenvironment and Response to Anti-PD-1 Therapy in Lung Adenocarcinoma.

MHC class II (MHCII) expression is usually restricted to APC but can be expressed by cancer cells. We examined the effect of cancer cell-specific MHCII (csMHCII) expression in lung adenocarcinoma on T cell recruitment to tumors and response to anti-PD-1 therapy using two orthotopic immunocompetent murine models of non-small cell lung cancer: CMT167 (CMT) and Lewis lung carcinoma (LLC). We previously showed that CMT167 tumors are eradicated by anti-PD1 therapy, whereas LLC tumors are resistant.

Tumor-intrinsic response to IFNγ shapes the tumor microenvironment and anti-PD-1 response in NSCLC.

Targeting PD-1/PD-L1 is only effective in ∼20% of lung cancer patients, but determinants of this response are poorly defined. We previously observed differential responses of two murine K-Ras-mutant lung cancer cell lines to anti-PD-1 therapy: CMT167 tumors were eliminated, whereas Lewis Lung Carcinoma (LLC) tumors were resistant. The goal of this study was to define mechanism(s) mediating this difference.

Activation of PPARγ in Myeloid Cells Promotes Progression of Epithelial Lung Tumors through TGFβ1.

Lung cancer is a heterogeneous disease in which patient-specific treatments are desirable and the development of targeted therapies has been effective. Although mutations in are frequent in lung adenocarcinoma, there are currently no targeted agents against KRAS. Using a mouse lung adenocarcinoma cell line with a mutation (CMT167), we previously showed that PPARγ activation in lung cancer cells inhibits cell growth yet promotes tumor progression when activated in myeloid cells of the tumor microenvironment.

Targeted overexpression of prostacyclin synthase inhibits lung tumor progression by recruiting CD4+ T lymphocytes in tumors that express MHC class II.

Lung-specific overexpression of prostacyclin synthase (PGIS) decreases tumor initiation in murine lung cancer models. Prostacyclin analogs prevent lung tumor formation in mice and reverse bronchial dysplasia in former smokers. However, the effect of prostacyclin on lung cancer progression has not been well studied.

Complement Activation via a C3a Receptor Pathway Alters CD4 T Lymphocytes and Mediates Lung Cancer Progression.

The complement cascade is a part of the innate immune system that acts primarily to remove pathogens and injured cells. However, complement activation is also peculiarly associated with tumor progression. Here we report mechanistic insights into this association in multiple immunocompetent orthotopic models of lung cancer.

The Tumor Microenvironment Regulates Sensitivity of Murine Lung Tumors to PD-1/PD-L1 Antibody Blockade.

Immune checkpoint inhibitors targeting the interaction between programmed cell death-1 (PD-1) and its ligand PD-L1 induce tumor regression in a subset of non-small cell lung cancer patients. However, clinical response rates are less than 25%. Evaluation of combinations of immunotherapy with existing therapies requires appropriate preclinical animal models.

Treatment of adult patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency: a clinical practice audit.

Objective: To review one physician's management of glucocorticoid replacement therapy in adult patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency and to determine the efficacy and the range of effective doses of dexamethasone in managing the clinical and biochemical consequences of this disorder.

Methods: We conducted a retrospective clinical practice audit of nine patients treated by a single physician for 21-hydroxylase deficiency during the period from March 1998 to January 2002. We documented biochemical control and clinical features of glucocorticoid excess or deficiency for various doses of dexamethasone.