Magee-Womens Hospital of UPMC's Rohit Bhargava and colleagues report in Modern Pathology that "immunohistochemistry is preferable to qRT-PCR for determination of estrogen and [progesterone receptor] expression." The researchers analyzed 464 breast cancer cases for ER and PR status using both immunohistochemistry and Genomic Health's Oncotype DX assay. They found good correlation between both approaches, though they write that immunohistochemistry was slightly more sensitive. "Immunohistochemistry offers additional advantages such as lower expense, ease of use, and faster turnaround time, the researchers say, later adding that "as qRT-PCR requires tissue microdissection and grinding for analysis, samples are inherently at risk for contamination with normal ductal breast tissue, fibroadipose tissue, inflammatory cells, biopsy cavities, and in situ carcinoma.
Also in Modern Pathology, researchers led by Oncolytics Biotech's Matthew Coffey examine the correlation between reovirus infection and cancer cell death. Using RT in situ PCR, the researchers found that, in patients treated with reovirus, most cancer cells harbored the viral genome. Further, they report that related cancer cell death is due to viral inhibition of microRNA-let-7d. "A key reason reovirus may be effective in destroying cancer cells is that the productive viral infection basically functions as an acute 'anti-microRNA' therapy," Coffey and colleagues write. "That is, the proliferating viral genome can acutely and markedly reduce microRNA-let-7d that, in turn, bypasses the normal 'caspase-apoptosis cascade' by markedly increasing the expression of caspase-3, that is the principle caspase responsible for the apoptotic death of these cancer cells."