BPTF activates the MAPK pathway through coexpression with Raf1 to promote proliferation of T‑cell lymphoma

Targeting CRAF kinase in anti-cancer therapy: progress and opportunities

The RAS/mitogen-activated protein kinase (MAPK) signaling cascade is commonly dysregulated in human malignancies by processes driven by RAS or RAF oncogenes. Among the members of the RAF kinase family, CRAF plays an important role in the RAS-MAPK signaling pathway, as well as in the progression of cancer. Recent research has provided evidence implicating the role of CRAF in the physiological regulation and the resistance to BRAF inhibitors through MAPK-dependent and MAPK-independent mechanisms. Nevertheless, the effectiveness of solely targeting CRAF kinase activity remains controversial. Moreover, the kinase-independent function of CRAF may be essential for lung cancers with KRAS mutations. It is imperative to develop strategies to enhance efficacy and minimize toxicity in tumors driven by RAS or RAF oncogenes. The review investigates CRAF alterations observed in cancers and unravels the distinct roles of CRAF in cancers propelled by diverse oncogenes. This review also seeks to summarize CRAF-interacting proteins and delineate CRAF's regulation across various cancer hallmarks. Additionally, we discuss recent advances in pan-RAF inhibitors and their combination with other therapeutic approaches to improve treatment outcomes and minimize adverse effects in patients with RAF/RAS-mutant tumors. By providing a comprehensive understanding of the multifaceted role of CRAF in cancers and highlighting the latest developments in RAF inhibitor therapies, we endeavor to identify synergistic targets and elucidate resistance pathways, setting the stage for more robust and safer combination strategies for cancer treatment.

An alternative NURF complex sustains acute myeloid leukemia by regulating the accessibility of insulator regions

Efficient treatment of acute myeloid leukemia (AML) patients remains a challenge despite recent therapeutic advances. Here, using a CRISPRi screen targeting chromatin factors, we identified the nucleosome-remodeling factor (NURF) subunit BPTF as an essential regulator of AML cell survival. We demonstrate that BPTF forms an alternative NURF chromatin remodeling complex with SMARCA5 and BAP18, which regulates the accessibility of a large set of insulator regions in leukemic cells. This ensures efficient CTCF binding and boundary formation between topologically associated domains that is essential for maintaining the leukemic transcriptional programs. We also demonstrate that the well-studied PHD2-BROMO chromatin reader domains of BPTF, while contributing to complex recruitment to chromatin, are dispensable for leukemic cell growth. Taken together, our results uncover how the alternative NURF complex contributes to leukemia and provide a rationale for its targeting in AML.