Evaluation of a region on chromosome 1p in ovarian serous carcinoma that is frequently deleted in uterine papillary serous carcinoma

PLK3 amplification and tumor immune microenvironment of metastatic tumors are linked to adjuvant treatment outcomes in uterine serous cancer

Uterine serous carcinoma (USC), an aggressive variant of endometrial cancer representing approximately 10% of endometrial cancer diagnoses, accounts for ∼39% of endometrial cancer-related deaths. We examined the role of genomic alterations in advanced-stage USC associated with outcome using paired primary-metastatic tumors (n = 29) treated with adjuvant platinum and taxane chemotherapy. Comparative genomic analysis of paired primary-metastatic patient tumors included whole exome sequencing and targeted gene expression. Both PLK3 amplification and the tumor immune microenvironment (TIME) in metastatic tumors were linked to time-to-recurrence (TTR) risk without any such association observed with primary tumors. TP53 loss was significantly more frequent in metastatic tumors of platinum-resistant versus platinum-sensitive patients and was also associated with increased recurrence and mortality risk. Increased levels of chr1 breakpoints in USC metastatic versus primary tumors co-occur with PLK3 amplification. PLK3 and the TIME are potential targets for improving outcomes in USC adjuvant therapy.

microRNAs as pharmacological targets in cancer

The survival rate of cancer patients has increased considerably in the last 20 years owing to significant efforts made in prevention, early detection protocols, combined chemotherapy regimens, targeted therapies, refined radiotherapy and cancer vaccines. However, metastasis and acquired resistance to current therapies represent two major challenges for achieving long-term cure. Therefore, new treatment strategies must be developed. One promising alternative is epigenetic-based therapies, of which miRNAs are at the forefront. MicroRNAs are endogenous small non-coding RNAs, often deregulated in cancer, which regulate gene expression by specific binding to the 3'-UTR of target genes. They are excellent candidates for therapy since miRNAs can regulate multiple targets of the same or different pathways, thereby minimizing the risk of resistance development or compensatory mechanisms. In this review, the mechanisms that lead to miRNA deregulation in cancer, their feasibility as therapeutic tools and the different strategies for the pharmacological manipulation of miRNAs in preclinical animal models are discussed.

Non-Endometrioid Adenocarcinoma of the Uterine Corpus: A Review of Selected Histological Subtypes

Background

Understanding the etiology, presentation, evaluation, and management of selected non-endometrioid endometrial adenocarcinomas of the uterine corpus is needed to define optimal treatment regimens.

Methods

The pathology and treatment of selected non-endometrioid endometrial adenocarcinomas of the uterus are reviewed and summarized.

Results

The most common non-endometrioid histology is papillary serous (10%), followed by clear cell (2% to 4%), mucinous (0.6% to 5%), and squamous cell (0.1% to 0.5%). Some non-endometrioid endometrial carcinomas behave more aggressively than the endometrioid cancers such that even women with clinical stage I disease often have extrauterine metastasis at the time of surgical evaluation. Therefore, when technically and medically feasible, comprehensive surgical staging is helpful for women with non-endometrioid endometrial cancer histology. Comprehensive surgical staging includes hysterectomy, bilateral salpingo-oophorectomy, pelvic and para-aortic lymphadenectomy, and cytological evaluation of the abdominal cavity. While whole abdominal radiotherapy has a limited role in early-stage uterine papillary serous carcinoma (UPSC) and clear cell carcinoma (CC), there may be a role for postoperative chemotherapy and volume-directed radiotherapy in both early-stage UPSC and CC. In the setting of optimally debulked advanced-stage disease, a combination of radiation and chemotherapy may be indicated. In the setting of recurrent disease or in women with residual disease after surgery, a platinum-based regimen or enrollment in a clinical trial is recommended.

Conclusions

UPSC and CC are managed similarly since sufficient data to separate treatment recommendations are lacking. Because both histologies are associated with a high rate of recurrence, adjuvant therapy is recommended even in women with early-stage disease. The remaining cell types should be treated similar to endometrioid or other low-grade histologies.

Opposite alterations of DNA methyltransferase gene expression in endometrioid and serous endometrial cancers

OBJECTIVE

To examine the DNA methyltransferase (DNMT) mRNA and protein levels in endometrioid and serous cancers and to study the relationship between DNA methyltransferase expression and endometrial cancer development.

METHODS

Normal endometrium, Grade I and Grade III endometrioid carcinoma tissues and cell lines, as well as serous cancer tissues, were analyzed for DNMT expression. Real-time PCR and Western blot techniques were employed to measure the mRNA and protein levels of the four DNA methyltransferases, DNMT1, DNMT2, DNMT3A, and DNMT3B. Immunohistochemistry was performed to detect alterations in DNMT nuclear localization and spatial organization patterns.

RESULTS

While DNMT2 and DNMT3A expression appear to be normal, two- to fourfold increase in DNMT1 and DNMT3B were found in both Grade I and Grade III endometrioid cancers. In addition, the poorly differentiated cell lines expressed relatively higher DNMT levels than well-differentiated cells. In contrast to endometrioid carcinomas, serous cancers expressed substantially lower levels of DNMT1 and DNMT3B than normal controls, with four- and twofold reduction observed in DNMT1 and DNMT3B mRNA levels, respectively. Western blot analysis confirmed opposite expression patterns of DNMT1 and DNMT3B protein in endometrioid and serous cancers. Immunohistochemistry showed normal nuclear localization of DNMT1 and DNMT3B in Type I and Type II cancer specimens as well as cell cultures.

CONCLUSION

Two opposite DNMT expression patterns were identified in endometrioid and serous cancers. The concerted upregulation in maintenance and de novo DNA methyltransferases in endometrioid carcinomas is consistent with a tendency for gene-specific hypermethylation observed in this histologic subtype, and may be implicated in tumor suppressor silencing. In contrast, the downregulation of maintenance and de novo DNA methyltransferases in serous cancers suggests that these tumors may contain hypomethylated genomic DNA, which has been associated with a higher mutation rate and is consistent with the known pathogenesis of serous-specific phenotypes. Taken together, the data suggest that divergent DNA methylation pathways may be implicated in the development of Type I and Type II endometrial cancers.

Endometrial glandular dysplasia: a putative precursor lesion of uterine papillary serous carcinoma. Part II: molecular features

Endometrial glandular dysplasia (EmGD) may be a newly defined precursor lesion of uterine papillary serous carcinoma (UPSC) by morphology. In this report, we studied molecular changes present in EmGD by the loss of heterozygosity (LOH) approach using laser capture microdissected tissue samples. Nineteen uteri showing at least 1 focus of EmGD by morphology were selected. These cases were 12 UPSC, 2 clear cell carcinomas, 1 mixed uterine papillary serous and endometrioid carcinoma, 1 uterine carcinosarcoma, 1 serous endometrial intraepithelial carcinoma (EIC), and 2 EmGD involving endometrial polyps. Seven microsatellite polymorphic DNA markers (TP53 at 17p, D1S211, and D1S162 at 1p32, D17S1323 at 17q21, D17S1330 at 17q25, D5S346 at 5q, and D2S123 at 2p) were utilized. A total of 123 laser-captured microdissection samples from 19 cases was studied with LOH method. The frequencies and patterns of LOH were analyzed and compared among benign resting endometrium (RE), EmGD, serous EIC, and UPSC. LOH was observed for at least 1 of the 7 markers in all categories of lesions, EmGD, serous EIC, and UPSC. The frequency of LOH for EmGD ranged from 4.2% to 31.3%; the range for serous EIC was 5.9% to 78.6%; and that for UPSC was 7.7% to 62.5%. The most frequent LOH in the 3 above-cited categories of lesions was identified at 17p (TP53) and 1p (D1S162). The frequency of LOH in EmGD with markers of TP53 and D1S162 was significantly higher than in RE (p < 0.05). With markers of D1S211 and D2S123, LOH in EmGD was higher than RE, approaching to a statistically significant level. Compared with foci of serous EIC and UPSC, however, the rate of LOH in EmGD was significantly lower only with TP53 locus (31.3% vs more than 60%, p < 0.05). The difference of LOH frequency with other chromosomal markers between EmGD and serous EIC/UPSC did not reach a statistically significant level. A significantly high concordant LOH pattern was found between foci of EmGD and serous EIC/UPSC (p = 0.05). We conclude that EmGD frequently shows LOH at multiple chromosomal loci, particularly at 17p and 1p. Significantly high concordant LOH frequency between EmGD and paired serous EIC or UPSC strongly suggests that EmGD is a noncancerous precursor lesion of UPSC, probably also of serous EIC. The clinical significance of EmGD needs further studies.