Expression of cyclin D1, D3, E, and p27 in human renal cell carcinoma analysed by tissue microarray

Abstract

Aberrations in the G1/S transition of the cell cycle have been observed in many malignancies and seem to be critical in the transformation process. Few studies have delineated the presence of G1/S regulatory defects and their clinical relevance in renal cell carcinoma (RCC). Therefore, we have examined the protein contents of cyclin D1, D3, E, and p27 in 218 RCCs, using tissue microarray and immunohistochemistry. The results from a subset of tumours were confirmed by Western blotting and immunohistochemical staining of regular tissue sections. Interestingly, low protein contents of cyclin D1 and p27 were associated with high nuclear grade, large tumour size, and poor prognosis for patients with conventional tumours. We further observed substantial differences in the pattern of G1/S regulatory defects between the different RCC subtypes. The majority of both conventional and papillary cases expressed p27; however, chromophobe tumours generally lacked p27 staining. In addition, conventional RCCs often expressed high cyclin D1 protein levels, while papillary RCCs exhibited high cyclin E. In summary, we have shown that G1/S regulatory defects are present in RCC and are associated with clinico-pathological parameters. The pattern of cell cycle regulatory defects also differed between RCC subtypes.

Figure 1

Illustration of cyclin D1, D3, E, and p27 immunohistochemistry staining of RCC using TMA technique. The left column illustrates a low protein expression, and the right column shows tumours with high content of the cell-cycle-regulating proteins.

Figure 2

Illustration of Western blot analysis of cyclin D1, D3, E, and actin in RCC. Actin was used as a loading control. The first lane, marked 9003 N, represents corresponding kidney cortex from patient 9003, whereas the tumour sample was loaded in lane 2. The other six lanes contain tumour samples to illustrate the variation in protein contents between the tumours.

Figure 3

Comparison between TMA-based immunohistochemistry analysis of cyclin D1, D3, E, and p27 (1–4) with (A) Western-blot-based analysis (cyclin D1, D3, and E) or (B) immunohistochemistry of regular sections (p27).

Figure 4

Kaplan–Meier survival curves for patients with conventional RCC: (A) cyclin D1 (low vs high levels); (B) p27 (low vs high levels).

Figure 5

An illustration of the combinations of alterations in cell cycle regulatory proteins in (A) 163 conventional, (B) 27 papillary, and (C) 13 chromophobe RCC. The light grey bars represent tumours having low p27 levels, while the dark grey bars represent tumours with high p27 levels. The presence of low and high cyclin expression are indicated as − and +.