A novel immunohistochemical method for estimating cell cycle phase distribution in ovarian serous neoplasms: implications for the histopathological assessment of paraffin-embedded specimens

Abstract

We have investigated whether immunohistochemical markers can identify differences in cell cycle phase distribution in ovarian serous neoplasms, including borderline tumours of different grades. Sections of normal ovary (n ¼ 18), serous cystadenoma (n ¼ 21), borderline serous tumours (n ¼ 21) and serous cystadenocarcinoma (n ¼ 15) were analysed by immunohistochemistry using markers of cell cycle entry (Mcm-2) and cell cycle phase, including cyclin D1 (mid-to-late G1), cyclin A (S phase), cyclin B1 (G2 phase) and phosphohistone H3 (mitosis). Double-labelling confocal microscopy confirmed marker phase specificity and phase estimations were corroborated by flow cytometry. On progression from normal ovary through serous cystadenoma and borderline tumours to cystadenocarcinomas, expression of Mcm-2 (Po0.0001), cyclin D1 (P ¼ 0.002), cyclin A (Po0.0001), cyclin B1 (Po0.0001) and phosphohistone H3 (Po0.0001) increased, paralleled by an increase in the S-phase fraction (cyclin A : Mcm-2 ratio; P ¼ 0.002). Borderline tumours of increasing grade also showed increased Mcm-2 and cyclin A expression, together with an increase in the Sphase fraction. Immunohistochemistry can be used to estimate cell cycle phase distribution in ovarian serous neoplasms, giving results similar to flow cytometric analysis and enabling direct assessment of tumour heterogeneity. Immunohistochemical estimates of the Sphase fraction may identify serous borderline tumours likely to exhibit malignant progression and/or select serous cystadenocarcinomas likely to respond to adjuvant therapy.

Immunohistochemical estimation of cell cycle phase in laryngeal neoplasia

“…However, our overall technique has previously been validated in surgical resection specimens of colorectal carcinoma and ovarian neoplasms, in which we showed that our immunohistochemical model resulted in comparable cell cycle phase analyses to those obtained by flow cytometry Scott et al, 2004). Nevertheless, confirmation of these observations by parallel flow cytometric and immunohistochemical analysis of laryngeal tumours will be important before commencing appropriately powered prognostic/predictive studies of larger numbers of samples.…”

“…Minichromosome maintenance protein 2 is one of six MCM proteins (MCMs 2 -7) that assemble in the prereplication complex and are essential for DNA replication in eukaryotic cells (Kearsey and Labib, 1998 six proteins are abundant throughout the cell cycle but are broken down rapidly on differentiation and more slowly in quiescence (Musahl et al, 1998). Antibodies against Mcm-2 have previously been shown to detect more cycling cells in laryngeal tissues than other 'proliferation' markers such as Ki67 (Chatrath et al, 2003), and immunohistochemical staining for Mcm-2 and/or Mcm-5 has been shown to be of value in identifying malignant or premalignant lesions in a range of clinical specimens (Williams et al, 1998;Freeman et al, 1999;Davies et al, 2002;Going et al, 2002;Chatrath et al, 2003;Scott et al, 2003;Sirieix et al, 2003;Scott et al, 2004).…”

Minichromosome maintenance protein 6, a proliferation marker superior to Ki-67 and independent predictor of survival in patients with mantle cell lymphoma

“…With the development of (Meng et al, 2001;Padmanabhan et al, 2004) and ovarian serous neoplasms (Scott et al, 2004) chondrosarcoma (Helfenstein et al, 2004), oligodendroglial tumours (Wharton et al, 2001(Wharton et al, , 2004, oesophageal neoplasm (Going et al, 2002), renal cell carcinoma (Dudderidge et al, 2005), breast cancer (Gonzalez et al, 2004), endometrial carcinoma (Li et al, 2005) and thyroid carcinoma (Guida et al, 2005).…”

“…Most of these studies focused on the detection of MCM2 (Freeman et al, 1999;Chatrath et al, 2003;Davidson et al, 2003;Kodani et al, 2003;Scott et al, 2004). So far only few investigations studied MCM6 expression (Labib et al, 2001;Helfenstein et al, 2004).…”

Immunodetection of phosphohistone H3 as a surrogate of mitotic figure count and clinical outcome in cutaneous melanoma

“…Thus, immunodetection of phosphohistone H3 has become a sensitive and specific marker of mitotic figures and correlates with outcome in a variety of different human tumor types, 9 including breast carcinoma, 10,11 colorectal adenocarcinoma, 12 ovarian serous adenocarcinoma, 13 pulmonary neuroendocrine carcinoma, 14 uterine smooth muscle tumors, 15 astrocytomas, 16 and meningiomas. 17 In melanoma, immunodetection of phosphohistone H3 has been shown to increase the sensitivity and accuracy for mitotic figure detection; it improves inter-observer variability; and it reduces the time required to identify mitoses in primary cutaneous and uveal melanomas.…”