This Week in Experimental and Molecular Pathology

In Experimental and Molecular Pathology, researchers at North Shore-Long Island Jewish Health System in New York report that sirolimus, which has been shown to inhibit the epithelial mesenchymal transition in a mouse model, modulates HIV-associated nephropathy, or HIVAN. Using a combination of immunohistochemical staining, western blotting, and RT-PCR, the researchers found that HIVAN model mice had increased levels of glomerular and tubular cells as compared to normal mice. But model mice given sirolimus has less renal cell proliferation. Further, HIVAN model mice receiving sirolimus had attenuated levels of ZEB1/2 and higher levesl of E-cadherin. "Since sirolimus attenuated renal cell ZEB expression (a repressor of E-cadherin transcription), it appears that sirolimus may be attenuating renal cell EMT by preserving epithelial cell E-cadherin expression," the researchers add.

Also in Experimental and Molecular Pathology, researchers led by Patrizio Caturegli at the Johns Hopkins Hospital write that expression of LMP2, an immunoproteasome subunit, can aid in telling renal oncocytoma and the eosinophilic variant of chromophobe renal cell carcinoma apart. Caturegli and his colleagues examined LMP2 expression in 56 renal oncocytoma, 38 chromophobe renal cell carcinoma, and 7 eosinophilic variant of chromophobe renal cell carcinoma cases as well as 84 normal kidney controls. They found that expression of LMP2 in the cytoplasm occured in each kind of renal lesion, though all eosinophilic chromophobe renal cell carcinoma cases had strong nuclear expression of LMP2 while the others did not. "These results suggest that the nuclear LMP2 expression can be used in clinical scenarios where histological distinction between RO and CHRCC-EO remains challenging," the authors add.