The association between p53 expression, stage and histological features in endometrial cancer

Does a p53 "Wild-type" Immunophenotype Exclude a Diagnosis of Endometrial Serous Carcinoma?

An aberrant p53 immunophenotype may be identified in several histotypes of endometrial carcinoma, and is accordingly recognized to lack diagnostic specificity in and of itself. However, based on the high frequency with which p53 aberrations have historically been identified in endometrial serous carcinoma, a mutation-type immunophenotype is considered to be highly sensitive for the histotype. Using an illustrative case study and a review of the literature, we explore a relatively routine diagnostic question: whether the negative predictive value of a wild-type p53 immunophenotype for serous carcinoma is absolute, that is, whether a p53-wild type immunophenotype is absolutely incompatible with a diagnosis of serous carcinoma. The case is an advanced stage endometrial carcinoma that was reproducibly classified by pathologists from 3 institutions as serous carcinoma based on its morphologic features. By immunohistochemistry, the tumor was p53-wild type (DO-7 clone), diffusely positive for p16 (block positivity), and showed retained expression of PTEN, MSH2, MSH6, MLH1, and PMS2. Next generation sequencing showed that there indeed was an underlying mutation in TP53 (D393fs*78, R213*). The tumor was microsatellite stable, had a low mutational burden (4 mutations per MB), and displayed no mutations in the exonuclease domain of DNA polymerase epsilon (POLE) gene. Other genomic alterations included RB1 mutation (R46fs*19), amplifications in MYST3 and CRKL, and ARID1A deletion (splice site 5125-94_5138del108). A review of the recent literature identified 5 studies in which a total of 259 cases of serous carcinoma were whole-exome sequenced. The average TP53 mutational rate in endometrial serous carcinoma was only 75% (range, 60 to 88). A total of 12 (33%) of 36 immunohistochemical studies reported a p53-aberrant rate of <80% in endometrial serous carcinoma. We discuss in detail several potential explanations that may underlie the scenario of serous carcinoma-like morphology combined with p53-wild-type immunophenotype, including analytic limitations, a nonserous histotype displaying morphologic mimicry of serous carcinoma, and true biological phenomena (including the possibility of a TP53-independent pathway of endometrial serous carcinogenesis). Ultimately, our central thematic question is provisionally answered in the negative. At present, the available data would not support a categorical conclusion that a p53 alteration is a necessary and obligate component in the genesis and/or diagnosis of endometrial serous carcinoma. On the basis of their collective experience, the authors proffer some recommendations on the use of p53 immunohistochemistry in the histotyping of endometrial carcinomas.

Endometrial Carcinoma: Specific Targeted Pathways

Endometrial cancer (EC) is the most common gynecologic malignancy in the western world with more than 280,000 cases per year worldwide. Prognosis for EC at early stages, when primary surgical resection is the most common initial treatment, is excellent. Five-year survival rate is around 70 %.Several molecular alterations have been described in the different types of EC. They occur in genes involved in important signaling pathways. In this chapter, we will review the most relevant altered pathways in EC, including PI3K/AKT/mTOR, RAS-RAF-MEK-ERK, Tyrosine kinase, WNT/β-Catenin, cell cycle, and TGF-β signaling pathways. At the end of the chapter, the most significant clinical trials will be briefly discussed.This information is important to identify specific targets for therapy.

SOX17 increases the cisplatin sensitivity of an endometrial cancer cell line

Background

Endometrial cancer (EC) is the most common form of malignant gynecological tumor. Treatment with cisplatin (CDDP) is the mainstay of EC chemotherapy. The apoptotic machinery is regarded as an important etiological factor in chemoresistance. Recent evidence has suggested that overexpression of the transcription factor SOX17 prevented apoptosis in tumor cell lines. The effect of SOX17 on apoptosis in EC cisplatin chemoresistance remains unclear.

Methods

Immunohistochemistry and the reverse transcription-polymerase chain reaction were employed to detect gene expression in paraffin-embedded EC tissues and blood samples. The anti-proliferative ability of SOX17 on EC cells was assessed by MTT. Flow cytometric analysis was used to detect cell apoptosis by annexin V/PI double-staining. The expression of apoptosis-related proteins was analyzed by western blot. In the in vivo study, nude mice were subcutaneously injected with EC cells, and received cisplatin treatment through intraperitoneal chemotherapy. Apoptosis of in vivo samples was analyzed by TUNEL assay.

Results

SOX17 expression decreased the chemical resistance of EC cells to CDDP. HEC-1B cells with an elevated expression of SOX17 had a lower cell viability and higher apoptosis rate after cisplatin exposure. Overexpression SOX17 up-regulated wild type p53 after being exposed to cisplatin, while the expression of BCL2-associated X protein and cleaved caspase-3 simultaneously increased. Caspase-9 inhibitor reduced the efficacy of SOX17 in HEC-1B cells after cisplatin treatment. In the in vivo study, SOX17 overexpression clearly restrained the tumor growth and increased the cisplatin toxicity and apoptosis of tumor cells.

Conclusions

SOX17 is involved in the p53-mediated apoptosis pathway, and increases the sensitivity of HEC-1B cells to cisplatin.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-016-0304-7) contains supplementary material, which is available to authorized users.

Identification of potential therapeutic targets by molecular profiling of 628 cases of uterine serous carcinoma

BACKGROUND

Therapeutic options are limited for uterine serous carcinoma (USC). TP53, PIK3CA, FBXW7, and ERBB mutations, as well as HER2 and EGFR overexpression have been reported. We aim to evaluate patterns of molecular, genomic and protein changes in 628USC tumors.

METHODS

628 consecutive cases of USC submitted to Caris Life Sciences from Mar, 2011 to July, 2014 were reviewed. These were analyzed using the Illumina TruSeq Amplcon Cancer panel to search for sequenced variants in 47 genes commonly implicated in carcinomatosis. In situ hybridization and immunohistochemistry were also used to assess copy number and protein expression, respectively, of selected genes.

RESULTS

31 out of 47 genes of interest harbored mutations, including TP53 (76%), PIK3CA (29%), FBXW7 (12%) and KRAS (9.3%). BRCA1 and BRCA2 were mutated in 9.1% and 6.3%, respectively. ERCC1 and MGMT were absent in 81% and 46% of tumors analyzed, respectively, suggesting potential benefit from platinum and alkylating agents. While not traditionally considered hormone-dependent, our cohort showed high ERα (60%), PR (32%), and AR (27%) expression. HER2 overexpression was 10% via IHC, amplification was 17% via CISH/FISH and mutation was 2% via NGS. While low in PTEN mutation frequency (7%), 45% of USC showed PTEN loss on IHC, and 29% harbored PIK3A mutation, suggesting deregulation of P13K/AKT pathway in a subset of patients. 11% expressed PDL1 and 67% expressed PD1.

CONCLUSIONS

Our findings suggest hormonal receptors, as well as genes implicated in DNA repair, cell proliferation and cell cycle pathways are of interest in USC.

Signalling pathways in endometrial cancer

Carcinogenesis is a multistage process, during which the activity of signalling pathways responsible for cell cycle regulation and division is disrupted which leads to inhibition of apoptosis and enhanced proliferation. Improper activation of Wnt/β-catenin and PI3K. Akt pathways play essential role in endometrial cancers (EC), mainly type I. Mutations in APC, axin or CTNBB1 may lead to β-catenin overactivation leading to excessive gene expression. PTEN inactivation, mutations in the PIK3CA or Akt result in increased transmission in the PI3K/Akt pathway, apoptosis inhibition, intensive cell division, mTOR excitation. In non-endometrioid cancers, key mutations include suppressor gene TP53 responsible for repairing damaged DNA or apoptosis initiation. Irregularities in gene P16, encoding a protein forming the p16-cyclinD/CDK-pRb have also been described. Understanding the complex relations between specific proteins taking part in signal transduction of the abovementioned pathways is key to research on drugs used in targeted therapy.

Development of targeted therapy in uterine serous carcinoma, a biologically aggressive variant of endometrial cancer

Endometrial cancer (EC) is the most common female genital malignancy in the USA. Most carcinomas arising from the uterus are estrogen dependent and are associated with obesity and hypertension. They are designated type I ECs and typically, due to their early diagnosis secondary to postmenopausal bleeding, have a good prognosis. By contrast, type II ECs develop in older patients, are not hormone dependent and are responsible for most recurrences and deaths from EC. Uterine serous cancer constitutes up to 10% of all endometrial tumors, and represents the most biologically aggressive variant of type II EC. This article will describe the most salient molecular markers that have been identified in uterine serous cancer, thus far with emphasis on the use of erbB2 (HER2/neu) as the first of a series of therapeutic markers for the treatment of this highly-aggressive subset of ECs.

Proteomics identification of cyclophilin a as a potential prognostic factor and therapeutic target in endometrial carcinoma

Endometrial carcinoma is one of the most common malignancies of the female genital tract, and there is an urgent need for discovery of novel factors for prognostic assessment and therapeutic targets to endometrial carcinoma. Herein a two-dimensional gel electrophoresis and MALDI-Q-TOF MS/MS-based proteomics approach was used to identify differentially expressed proteins in endometrial carcinoma. Of the 99 proteins identified, cyclophilin A was one of the most significantly altered proteins, and its overexpression was confirmed using RT-PCR and Western blot analyses. Immunohistochemistry suggested a link between cyclophilin A expression and poor differentiation and decreased survival (p < 0.01). Knockdown of cyclophilin A expression by RNA interference led to the significant suppression of the cell growth and the induction of apoptosis in endometrial carcinoma HEC-1-B cells in vitro (p < 0.01) and the inhibition of tumor growth in vivo (p < 0.01). These data suggest that cyclophilin A may serve as a novel prognostic factor and possibly an attractive therapeutic target for endometrial carcinoma.

Endometrial carcinoma: pathology and genetics

In the Western world, endometrial carcinoma is the most common malignant tumour of the female genital tract and the fourth most common cancer in women after carcinomas of breast, colorectum, and lung. The annual incidence has been estimated at 10-20 per 100 000 women. In the United States, endometrial carcinoma accounts for approximately 6000 deaths per year. Two different clinicopathological subtypes are recognised: the oestrogen-related (type I, endometrioid) and the non-oestrogen related (type II, non-endometrioid). The clinicopathological differences are parallelled by specific genetic alterations, with type I showing microsatellite instability and mutations in PTEN, PIK3CA, K-Ras, and CTNNB1 (beta-catenin), and type II exhibiting p53 mutations and chromosomal instability. This article reviews the genetic changes of endometrial carcinogenesis in the light of morphological features of the tumours and their precursors.

The management of serous papillary uterine cancer

PURPOSE OF REVIEW

Uterine papillary serous cancer is an extremely aggressive cancer, the optimum management of which is still being determined. It is important to understand advances that have been made in 2005 regarding the molecular biology, diagnosis, and management of this deadly disease.

RECENT FINDINGS

The main themes in the literature regarding uterine papillary serous cancer are that a potential precursor lesion, serous endometrial intraepithelial carcinoma, has been recognized as an early form of the disease. A variety of molecular biologically important markers have now been identified, including p53, HER2/neu, IL-6, kallikrein 6, and claudin-4, some of which may be susceptible to molecularly targeted therapy. Systematic surgical staging is necessary before additional therapy is recommended. Stage I uterine papillary serous cancer requires aggressive treatment, including surgery, chemotherapy, and radiation therapy for successful treatment. The most effective management of advanced stage disease remains to be resolved.

SUMMARY

Serous endometrial intraepithelial carcinoma should be treated as a form of uterine papillary serous cancer. Multimodality therapy is required for the successful management of early stage uterine papillary serous cancer. Advanced disease is often unresponsive to conventional therapy. Molecularly targeted therapies are now being introduced into the management of this disease.

Molecular alterations in the pathogenesis of endometrial adenocarcinoma. Therapeutic implications

Molecular genetic evidence indicates that endometrial carcinoma likely develops as the result of a multistep process of oncogene activation and tumor suppressor gene inactivation. These molecular alterations appear to be specific for Type I (endometrioid) and Type II (non endometrioid) cancers. Type I cancers are characterized by mutation of PTEN, KRAS2, defects in DNA mismatch repair, as evidenced by the microsatellite instability phenotype, and a near diploid karyotype. Type II cancers often contain mutations of TP53 and Her-2/neu and are usually nondiploid. The clinical value of many of these molecular markers is now being tested and it may help to refine diagnosis and establish an accurate prognosis. Furthermore, some of these tumor biomarkers constitute the targets for emerging therapies. Transtuzumab against Her-2/neu and bevacizumab against VEGF overexpressing carcinomas are among the promising novel treatments. Additional translational research is needed to identify molecular and genetic alterations with potential for therapeutic interventions.