• hematologic cancer

Mutations in the Drosophila gene mxc produce a model of hematologic cancer. Dmel\mxc protein localizes to the histone locus body and is involved in hemocyte differentiation and proliferation. Several alleles of mxc have been generated, including hypomorphs and RNAi targeting constructs.

There is no clear ortholog for mxc in humans.

In mxc¹ mutants, larval lymph glands (fly hematopoietic organs) exhibit hyperplasia while other discs are undersized, and flies die as larvae or pupae. Abnormal mutant hemocytes, transplanted to a host recipient, will invade tissues and eventually kill the host. Several immune-related genes including antimicrobial peptides (FBgg0001101) are upregulated in mutant lymph glands. This appears to be a response to rather than a mechanism of carcinogenesis. Overexpression of the Toll pathway by Dl and the Imd pathway by Rel suppress the hyperplastic phenotype. Furthermore, ectopic expression of antimicrobial peptides (AMPs) in the fat body (a fly organ with functions similar to the liver), increases apoptosis in the mxc mutant lymph gland, but not in other tissues or wild-type lymph gland.

[updated November 2019 by FlyBase; FBrf0222196]