CD320 Knockout NCI-H1299 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human NCI-H1299 cell line, designed for loss-of-function analysis of the CD320 gene. This polyclonal product provides a heterogeneous pool of cells with targeted disruptions at the CD320 locus, enabling robust functional studies without clonal selection biases. It serves as a versatile in vitro model for investigating the transcobalamin receptor??s role in vitamin B12 homeostasis and downstream metabolic pathways.
The parental NCI-H1299 cell line is an epithelial non-small cell lung cancer (NSCLC) model established from lymph node metastasis of a lung adenocarcinoma. It is characterized by TP53 deletion (p53 null) and an activating KRAS mutation, genetic hallmarks of aggressive NSCLC. These oncogenic alterations drive proliferation and metabolic reprogramming, making NCI-H1299 a relevant background for exploring cancer metabolism and micronutrient uptake, particularly the interplay between oncogenic signaling and one-carbon metabolism.
CD320 encodes the transcobalamin receptor (TCblR), which mediates endocytosis of the transcobalamin II (TCN2)?Cvitamin B12 complex. Its activity is regulated by TCN2 and vitamin B12 status, and it interacts with LRP2. Internalized B12 is a cofactor for methionine synthase (MTR) and methylmalonyl-CoA mutase (MUT). CD320 knockout blocks uptake, causing B12 deficiency, impaired MTR and MUT, and accumulation of homocysteine and methylmalonic acid, thus disturbing one-carbon metabolism involving CBS and MTHFR.
In the p53-null, KRAS-mutant NCI-H1299 background, CD320 deletion allows dissection of vitamin B12 dependency in NSCLC metabolism. Cancer cells often rely on B12-dependent methionine synthesis and methylation pathways for proliferation. This model helps elucidate how loss of CD320-mediated B12 transport impacts methionine availability, SAM/SAH ratios, and metabolic flexibility under oncogenic stress. Moreover, it provides a platform to validate CD320 as a target for B12-conjugated drug delivery, given the receptor??s role in cellular uptake.
These polyclonal knockout cells are suitable for B12 uptake assays, LC-MS quantification of homocysteine and methylmalonic acid, western blotting and RT-qPCR for CD320 confirmation, and viability assays under B12-limited conditions. Applications include mechanistic studies of cobalamin transport defects, metabolic modeling of methylmalonic aciduria and homocystinuria, and evaluation of TCblR-targeted therapeutics in lung cancer. For further information, please contact Ascent Research.
