Immunohistochemical study of DNA topoisomerase I, p53, and Ki-67 in uterine carcinosarcomas

Inter‑component immunohistochemical assessment of proliferative markers in uterine carcinosarcoma

In the scientific literature, a selected number of reports have investigated the impact of proliferative activity on the development and progression of uterine carcinosarcomas (UC). The aim of the present retrospective study was to compare the immunohistochemical proliferation markers [Ki67, proliferating cell nuclear antigen (PCNA), minichromosome maintenance complex component 3 (MCM3), and topoisomerase IIα (topoIIα)] assessment in both components of UC. A total of 30 paraffin-embedded slides of UCs, obtained from patients who underwent surgery between January 1, 2006, and December 31, 2020, were analyzed. Medical records and clinicopathological data of patients were reviewed. Formalin-fixed, paraffin-embedded tissue sections were immunostained with monoclonal antibodies against Ki67, PCNA, MCM3 and topoIIα. Ki67-positive nuclear immunoreactivity was reported in 20 (67%) and 16 (53%) UC carcinomatous and sarcomatous components, respectively. In the epithelial component, Ki67 positive staining was related to the International Federation of Gynecology and Obstetrics (FIGO) stage (P=0.025), and histological grade (G1 vs. G2/G3, P=0.031). Nuclear PCNA reactivity was observed in 18 (60%) and 16 (53%) carcinomatous and sarcomatous components, respectively. Notably, all four cases with omental metastases were PCNA-positive, and a relationship between staining pattern and the existence of metastases was of significant value (P=0.018). MCM3-positive nuclear staining was found nearly twice as high in the carcinomatous (n=19; 63%), compared with the sarcomatous (n=11; 37%) component, respectively, and MCM3 expression in the epithelial component was related to clinical stage (P=0.030), and the existence of omental metastasis (P=0.012). In addition, out of the 30 UCs, 17 (57%) and 13 (43%) showed topoIIα positivity in the carcinomatous and sarcomatous UC components, respectively. A significant relationship between protein immunoreactivity and FIGO stage (P=0.049), and omental metastasis (P=0.026) was revealed to exist. However, no significant differences between expression of proliferation markers and clinicopathological features in the sarcomatous UC component were identified. Finally, a significant correlation between each protein immunohistochemical staining was demonstrated, particularly in the sarcomatous UC component. Collectively, a combined analysis of Ki67, PCNA, MCM3, and topoIIα may provide more detailed information of cell-cycle alterations determining the heterogeneity of uterine carcinosarcomas.

Epithelial to mesenchymal transition in the pathogenesis of uterine malignant mixed Müllerian tumours: the role of ubiquitin proteasome system and therapeutic opportunities

Malignant mixed Müllerian tumours (malignant mixed mesodermal tumours, MMMT) of the uterus are metaplastic carcinomas with a sarcomatous component and thus they are also called carcinosarcomas. It has now been accepted that the sarcomatous component is derived from epithelial elements that have undergone metaplasia. The process that produces this metaplasia is epithelial to mesenchymal transition (EMT), which has recently been described as a neoplasia-associated programme shared with embryonic development and enabling neoplastic cells to move and metastasise. The ubiquitin proteasome system (UPS) regulates the turnover and functions of hundreds of cellular proteins. It plays important roles in EMT by being involved in the regulation of several pathways participating in the execution of this metastasis-associated programme. In this review the specifi c role of UPS in EMT of MMMT is discussed and therapeutic opportunities from UPS manipulations are proposed.

Morphologic manifestations of gene-specific molecular alterations ("genetic addictions") in mouse models of disease

Neoplasia in both animals and humans results in part from lasting activation of tumor-promoting genes ("oncogenes") or diminished function of genes responsible for preventing neoplastic induction ("tumor suppressor genes"). The concept of "genetic addiction" has emerged to indicate that neoplastic cells cannot maintain a malignant phenotype without sustained genotypic abnormalities related to aberrant activity of oncogene(s) and/or inactivity of tumor suppressor gene(s). Interestingly, some genetic abnormalities reliably produce distinct morphologic patterns that can be used as structural signatures indicating the presence of a specific molecular alteration. Examples of such consistent genetic/microanatomic pairings have been identified for mutated oncogenes, such as rising mucin-producing capacity with RAS overexpression, and mutated tumor suppressor genes-including PTEN eliciting cell hypertrophy, RB1 dictating neuroendocrine differentiation, and TRP53 encouraging sarcomatous transformation. Familiarity with the concept of genetic addiction, as well as the ability to recognize such regular genomic-phenotypic relationships, are of paramount importance for comparative pathologists who are engaged in phenotyping genetically engineered mice to help unravel genomic intricacies in both health and disease.

Molecular markers and clinical behavior of uterine carcinosarcomas: focus on the epithelial tumor component

Carcinosarcomas (malignant mixed Müllerian tumors) of the uterus are rare and aggressive malignancies consisting of an epithelial (carcinoma) and a mesenchymal (sarcoma) tumor component and are considered as metaplastic endometrial carcinomas. This study evaluated molecular characteristics and clinical behavior of uterine carcinosarcomas to improve treatment regimens in the future. Immunohistochemical expression of estrogen receptor-α and -β, progesterone receptor-A and -B, MLH1, MSH2, MSH6, PTEN (phosphatase and tensin homolog deleted on chromosome 10), p53, β-catenin and cyclin D1 was determined in 40 uterine carcinosarcomas. Immunostaining was compared between epithelial and mesenchymal tumor components. To determine the prognostic role of the epithelial component, clinicopathological data and survival were compared between patients with endometrioid and non-endometrioid epithelial tumor components. To determine prognosis of carcinosarcomas compared with high-risk endometrial carcinomas, clinicopathological characteristics and survival were compared between these patients. Hormone receptor expression occurred infrequently: estrogen receptor-α (8%) and -β (32%), progesterone receptor-A (0%) and -B (23%), next to β-catenin (4%) and cyclin D1 (7%). PTEN, MLH1, MSH2 and MSH6 mutations occurred in 39%, 33%, 22% and 21%, respectively (based on absent immunostaining). Overexpression of p53 was observed in 38%. Expression patterns of p53, MSH2 and MSH6 corresponded between epithelial and mesenchymal tumor components. In our cohort, the epithelial component caused the majority of metastases (72%) and vascular invasion (70%). Survival tended to be worse for patients with a non-endometrioid epithelial component compared with an endometrioid epithelial component (5-year survival: 26% and 55%, respectively). Survival was worse for patients with uterine carcinosarcomas compared with high-risk endometrial carcinomas (grade 3 endometrioid and non-endometrioid); 5-year survival rates: 42%, 77% and 57%, respectively. Our results support the monoclonal origin of uterine carcinosarcomas. The epithelial component determines prognosis by causing the majority of metastases and vascular invasion. To improve prognosis, treatment should focus on the epithelial tumor component of uterine carcinosarcomas.