NSD2 contributes to oncogenic RAS-driven transcription in lung cancer cells through long-range epigenetic activation

Area of Science:

• Oncology
• Epigenetics
• Molecular Biology

Background:

• The histone methyltransferase NSD2 (also known as WHSC1/MMSET) is overexpressed in several solid tumors.
• Its specific role in tumor biology, particularly in lung cancer, remains unclear.

Purpose of the Study:

• To investigate the contribution of NSD2 to lung cancer cell proliferation.
• To explore the molecular mechanisms by which NSD2 influences oncogenic RAS transcriptional responses.
• To evaluate the potential of combinatorial therapies involving NSD2 inhibition.

Main Methods:

• NSD2 knockdown experiments in lung cancer cell lines.
• Treatment with MEK and BRD4 inhibitors.
• Analysis of gene expression and transcriptional responses.
• Chromatin immunoprecipitation assays to examine H3K36me2 marks.

Main Results:

• NSD2 knockdown inhibited proliferation in a subset of lung cancer cell lines by affecting oncogenic RAS transcriptional responses.
• Combined NSD2 knockdown with MEK or BRD4 inhibitors demonstrated cooperative inhibitory effects on cell growth.
• NSD2 inhibition impacted gene clusters within H3K36me2-marked megabase-scale regions involved in the RAS transcription program.
• MEK and BRD4 inhibitors downregulated genes associated with cancer-acquired super-enhancers.

Conclusions:

• NSD2 plays a role in lung cancer proliferation by supporting oncogenic RAS signaling.
• Combinatorial therapy with NSD2 inhibitors and MEK or BRD4 inhibitors may offer a more comprehensive approach to inhibit RAS-driven transcription programs in lung cancers overexpressing NSD2.