Background: Mutations in KRAS and BRAF genes are prevalent in colorectal cancer (CRC), which strikingly promote tumorigenesis and lead to poor response to a variety of treatments including immunotherapy by activating the MAPK/ERK pathway. Thus, there is an urgent need to discover effective therapeutic targets and strategies.
Methods: CRISPR-Cas9 lentiviral knockout library was used to screen the suppressors of anti-PD1 immunotherapy. Bioinformatic analysis was used to analyze the correlation between PHF8 expression and immune indicators in CRC. In vitro and in vivo experiments were utilized to determine the effects of PHF8 on the immune indexes and malignant phenotypes of CRC cells. qRT-PCR, western blotting, immunohistochemical (IHC) staining, and chromatin immunoprecipitation (ChIP)-qPCR assays were used to determine the regulatory effects of PHF8 on PD-L1, KRAS, BRAF, and c-Myc and the regulatory effect c-Myc/miR-22-3p signaling axis on PHF8 expression in CRC cells.
Results: This study identified histone lysine demethylase PHF8 as a negative regulator for the efficacy of anti-PD1 therapy and found that it was highly expressed in CRCs and strongly associated with poor patient survival. Functional studies showed that PHF8 played an oncogenic role in KRAS- or BRAF-mutant CRC cells, but not in wild-type ones. Mechanistically, PHF8 up-regulated the expression of PD-L1, KRAS, BRAF, and c-Myc by increasing the levels of transcriptional activation marks H3K4me3 and H3K27ac and decreasing the levels of transcriptional repression mark H3K9me2 within their promoter regions, promoting immune escape and tumor progression. Besides, our data also demonstrated that PHF8 was up-regulated by the c-Myc/miR-22-3p signaling axis to form a positive feedback loop. Targeting PHF8 substantially improved the efficacy of anti-PD1 therapy and inhibited the malignant phenotypes of KRAS- or BRAF-mutant CRC cells.
Conclusion: Our data demonstrate that PHF8 may be an effective therapeutic target for KRAS- or BRAF-mutant CRCs.
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http://dx.doi.org/10.1186/s13046-025-03338-2 | DOI Listing |
J Exp Clin Cancer Res
February 2025
Department of Endocrinology and International Joint Research Center for Tumor Precision Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, P.R. China.
Background: Mutations in KRAS and BRAF genes are prevalent in colorectal cancer (CRC), which strikingly promote tumorigenesis and lead to poor response to a variety of treatments including immunotherapy by activating the MAPK/ERK pathway. Thus, there is an urgent need to discover effective therapeutic targets and strategies.
Methods: CRISPR-Cas9 lentiviral knockout library was used to screen the suppressors of anti-PD1 immunotherapy.
Ann Oncol
January 2025
Division of Pathology & Data Analytics, Leeds Institute of Medical Research, University of Leeds, Leeds, UK.
Background: The FOxTROT trial has reported advantages of neoadjuvant chemotherapy (NAC) in locally advanced colon cancer (LACC). In this article, we present results of the embedded randomised phase II trial testing the addition of panitumumab to neoadjuvant FOLFOX compared with FOLFOX alone in RAS and BRAF-wild-type (wt) patients and with biomarker hyperselection.
Patients And Methods: Patients had operable, computed tomography-predicted stage T3-4, N0-2, M0 colon adenocarcinoma.
Mol Cancer Res
January 2024
University of Oxford, Oxford, United Kingdom.
BRAF mutations in colorectal cancer (CRC) comprise three functional classes: Class 1 (V600E) with strong constitutive activation, Class 2 with pathogenic kinase activity lower than Class 1, and Class 3 which paradoxically lacks kinase activity. Non-Class 1 mutations associate with better prognosis, microsatellite stability, distal tumour location and better anti-EGFR response. Analysis of 13 CRC cohorts (n=6,605 tumours) compared Class 1 (n=709, 10.
View Article and Find Full Text PDFJ Transl Med
December 2024
Candiolo Cancer Institute, FPO-IRCCS, Candiolo, TO, Italy.
Background: Colorectal cancer (CRC) is the third most common cancer worldwide, with highly variable prognosis and response to treatment. A large subset of patients does not respond to standard treatments or develops resistance. As an alternative, adoptive immunotherapy based on chimeric antigen receptor (CAR)-transduced immune cells has been proposed, however with significant adverse events.
View Article and Find Full Text PDFGenes (Basel)
October 2024
Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA.
Although V600E mutations are common in solid tumors and select hematologic neoplasms, they are reported less frequently in myeloid malignancies. Of the cases of V600E-mutant acute myeloid leukemia (AML) that have been described, most display monocytic morphology and concurrent rearrangement. Strikingly, all cases have been associated with poor survival.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!