The detection of renal carcinoma cells in the peripheral blood with an enhanced reverse transcriptase-polymerase chain reaction assay for MN/CA9

Abstract

BACKGROUND Using a reverse transcriptase–polymerase chain reaction (RT‐PCR) assay, the authors previously determined the expression of MN/CA9 mRNA in renal cell carcinoma (RCC) and its absence in benign renal tissue. In the current study, the utility of an enhanced RT‐PCR assay in the detection of renal carcinoma cells in the peripheral blood was assessed. METHODS An enhanced MN/CA9 RT‐PCR assay was applied to peripheral blood samples from a total of 96 patients. Forty‐two patients had renal tumors, including 5 with benign renal lesions, 28 with localized RCC, and 9 with metastatic RCC. Fifty‐four control patients without renal tumors were similarly tested. Pathologic staging for patients with localized cancer was T1N0M0 for 5, T2N0M0 for 9, and T3N0M0 for 14 patients. RESULTS Cells expressing MN/CA9 were detected in 1 of 54 controls (1.8%) and in 18 of 37 cancer patients (49%). Thirteen of twenty eight patients (46%) with localized RCC and 5 of 9 (56%) with metastatic disease tested positive with the assay. No patient with a benign renal tumor exhibited MN/CA9 expression. All blood test results for patients with clear cell RCC were noted to be positive. No correlation was noted between MN/CA9 results and age, gender, or tumor grade. The differences in MN/CA9 results according to T classification were not statistically significant. CONCLUSIONS The enhanced RT‐PCR assay for MN/CA9 is a highly specific technique for detecting circulating renal carcinoma cells in the peripheral blood, and it may prove useful in the diagnosis and monitoring of RCC. Cancer 1999;86:492–7. © 1999 American Cancer Society.

Carbonic anhydrase IX is a clinically significant tissue and serum biomarker associated with renal cell carcinoma

“…Bluemke and colleagues screened the status of CTCs in the blood samples from renal carcinoma patients and revealed that the presence of CTCs correlated with the lymph node status and synchronous metastasis (9). The ability to detect CTCs by analyzing the expression of CA9 as a tumor-specific biomarker in blood samples has previously been reported (10)(11)(12)(13). RT-PCR for CA9 is a highly specific and sensitive technique for detecting CTCs shed from renal carcinomas.…”

“…McKiernan et al assessed CA9-expressing cells in 49% of a total of 37 RCC patients. Using the primers designated against exons 1 and 5, they detected the two variants of CA9 mRNA and, therefore, they did not reveal any correlation between CA9 expression and age, gender or tumor grade (10). The same set of primers with contrasting results was used in a further two studies.…”

Carbonic anhydrase inhibitor suppresses invasion of renal cancer cells in vitro

“…Among these, CA II and CA IV have been identified in the mammalian kidney and implicated in the acidification of the excreted tubule fluid (22). Two more recently characterized transmembrane isoenzymes, CA IX and CA XII, are overexpressed in renal cell carcinomas and down-regulated by the product of the von Hippel-Lindau tumor suppressor gene (11,12,23,24). Based on immunocytochemistry and Western blotting of renal cancer cells, we can conclude that the effect of acetazolamide on invasion capacity is most likely attributable to inhibition of CA II and͞or CA XII.…”

Detection and enrichment of disseminated renal carcinoma cells from peripheral blood by immunomagnetic cell separation

“…[32][33][34][35][36] To our knowledge, only 1 report has described the detection of disseminating tumor cells in RCC patients by applying RT-PCR for MN/CA9 mRNA. 20 After examining blood samples, they found circulating tumor cells in 49% of localized and in 59% of metastatic RCC patients. All positive samples originated from patients with RCC of the clear-cell type; in contrast, tumor-specific MN/CA9 mRNA could not be found in any of the patients with benign renal tumors.…”

“…4 -7 Immunomagnetic cell-enrichment experiments could detect disseminated tumor cells for breast carcinoma, 8 -13 colon carcinoma, 14 -16 ovarian carcinoma, 12 head-and-neck squamous-cell carcinoma 17 and melanoma. 18 For renal-cell carcinoma (RCC), the dissemination of tumor cells in the bone marrow 19 and the detection of tumor-associated MN/CA9 mRNA in blood 20 have been reported.…”