MLH1 Knockout Cell Line (HEK293)

The choice depends on whether you are studying MLH1's role as the principal MutL family scaffold for human mismatch repair or modeling Lynch syndrome (HNPCC). The Knockout line is the standard tool for asking whether MLH1 is required for MMR — MLH1 is the obligate partner of PMS2 (forming MutLα), PMS1 (forming MutLβ), and MLH3 (forming MutLγ); MLH1 loss destabilizes all three MutL complexes and abolishes canonical MMR activity. Overexpression is useful for studying MLH1 in heterologous expression contexts or for testing disease-associated mutations. For mismatch repair research, the EDITGENE MLH1 Knockout in HEK293 is the most consequential single MMR knockout — MLH1 loss eliminates all MutL function and is the most common cause of Lynch syndrome (~50% of HNPCC cases). MLH1 promoter hypermethylation is the principal mechanism of sporadic MMR deficiency in colorectal cancer. Rescue with wild-type or disease-associated mutant MLH1 enables comprehensive disease genotype-function studies. This product complements the parallel PMS2, MSH6, MSH3 Knockouts in HEK293 for systematic MMR pathway dissection. The knockout is critical for studying immune checkpoint inhibitor response — MMR-deficient cancers have FDA-approved indications for pembrolizumab tissue-agnostic therapy.

Primary applications: • Mismatch repair activity: in vitro MMR reconstitution assays — MLH1 loss eliminates all MutL function, providing the most complete MMR null background. • Microsatellite instability: BAT-25, BAT-26, and other repeat tract stability analysis. • Lynch syndrome modeling: rescue with patient-derived MLH1 mutations for genotype-function studies — MLH1 mutations cause ~50% of Lynch syndrome cases. • Immune checkpoint inhibitor response: pembrolizumab and dostarlimab sensitivity studies given MMR-deficient cancer's FDA-approved checkpoint inhibitor indications. • MLH1 promoter hypermethylation modeling: sporadic MMR-deficient colorectal cancer mechanism studies. EDITGENE recommends this model for researchers investigating MMR pathway integrity, Lynch syndrome mechanisms, MSI-high cancer immunotherapy, and combined MMR pathway dissection (alongside parallel PMS2, MSH6, MSH3 KOs in HEK293).

Yes. MLH1 rescue experiments are well-established for MMR research: • Construct design: use a codon-modified MLH1 sequence with a small C-terminal tag (FLAG, HA). MLH1 has N-terminal ATPase domain, central CTH-binding region, and C-terminal MutL homology domain (PMS2/PMS1/MLH3 binding) — preserve all elements. • ATPase-deficient rescue: K84A mutation in the ATP-binding lysine abolishes MMR activity and is the standard specificity control. • MutL partnership: MLH1 stabilizes PMS2, PMS1, and MLH3 — rescue restores all MutL complexes simultaneously. • Lynch syndrome mutation rescue: patient-derived MLH1 mutations enable disease genotype-function studies — particularly relevant given MLH1's central scaffolding role in MMR. • Functional readout: rescue should restore MMR activity, microsatellite stability, and 6-thioguanine sensitivity. HEK293 transduces efficiently with lentivirus and supports stable rescue line generation.