The KRAS-variant and miRNA expression in RTOG endometrial cancer clinical trials 9708 and 9905

High-intermediate risk endometrial cancer: moving toward a molecularly based risk assessment profile

In the USA, endometrial cancer (EMCA) incidence is increasing as the risk factors of obesity, diabetes, and hypertension become more prevalent. Although most EMCA is detected at an early stage and surgical intervention is curative, a subset of patients termed 'high-intermediate risk' (H-IR) experience an increased rate of recurrence. Unfortunately, adjuvant therapies in patients with H-IR EMCA have yet to increase overall survival. Historically, stratification of these patients from their low-risk counterparts incorporated clinical and pathologic findings. However, due to developments in molecular testing and genomic sequencing, tumor biomarkers are now being incorporated into the risk-assessment criteria in the hope of finding molecular profile(s) that could highlight treatment regimens that will increase patient survival. Since modern research aims to accurately identify patients with a higher risk of recurrence and develop effective interventions to improve patient survival, these molecular-based analyses could allow for an enhanced understanding of a patient's true risk of recurrence to facilitate the rise of personalized medicine. This review summarizes key clinical trials and recent advances in molecular and genomic profiles that have influenced current treatment regimens for patients with H-IR EMCA and laid the foundation for subsequent research.

The Role of miRNAs in the Regulation of Endometrial Cancer Invasiveness and Metastasis-A Systematic Review

Endometrial cancer (EC) is the most common genital cancer in women with increasing death rates. MiRNAs are short non-coding RNAs that regulate gene expression on the post-transcriptional levels. Multiple studies demonstrated a fundamental role of miRNAs in the regulation of carcinogenesis. This systematic review is a comprehensive overview of the role of miRNAs in the regulation of cancer cell invasiveness and metastasis in EC. The literature was searched for studies investigating the role of miRNAs in the regulation of invasiveness and metastasis in EC. We explored PubMed, Embase, and Scopus using the following keywords: miRNA, metastasis, invasiveness, endometrial cancer. Data were collected from 163 articles that described the expression and role of 106 miRNAs in the regulation of EC invasiveness and metastasis out of which 63 were tumor suppressor miRNAs, and 38 were oncomiRNAs. Five miRNAs had a discordant role in different studies. Moreover, we identified 66 miRNAs whose expression in tumor tissue or concentration in serum correlated with at least one clinical parameter. These findings suggest a crucial role of miRNAs in the regulation of EC invasiveness and metastasis and present them as potential prognostic factors for patients with EC.

The landscape of gene mutations and clinical significance of tumor mutation burden in patients with soft tissue sarcoma who underwent surgical resection and received conventional adjuvant therapy

BACKGROUND

The aim of this study was to evaluate the landscape of gene mutations and the clinical significance of tumor mutation burden (TMB) in patients with soft tissue sarcoma who underwent surgical resection and received conventional adjuvant therapy.

METHODS

A total of 68 patients with soft tissue sarcoma were included. Postoperative tumor tissue specimens from the patients were collected for DNA extraction. Targeted next-generation sequencing of cancer-relevant genes was performed for the detection of gene mutations and the analysis of TMB. Univariate analysis between TMB status and prognosis was carried out using the Kaplan-Meier survival analysis, and multivariate analysis was adjusted by the Cox regression model.

RESULTS

No specific genetic mutations associated with soft tissue sarcoma were found. The mutation frequency of TP53, PIK3C2G, NCOR1, and KRAS of the 68 patients with soft tissue sarcoma were observed in 19 cases (27.94%), 15 cases (22.06%), 14 cases (20.59%), and 14 cases (20.59%), respectively. With regard to the analysis of TMB, the overall TMB of the 68 patients with soft tissue sarcoma was relatively low (median: 2.05 per Mb (range: 0∼15.5 per Mb)). Subsequently, TMB status was divided into TMB-Low and TMB-Middle according to the median TMB. Patients with TMB-Low and TMB-Middle were 37 cases (54.41%) and 31 cases (45.59%), respectively. Overall survival analysis indicated that the median overall survival of patients with TMB-Low and TMB-Middle was not reached, and 4.5 years, respectively (P=0.015).

CONCLUSION

This study characterizes the genetic background of patients with STS soft tissue sarcoma. The TMB was of clinical significance for patients with soft tissue sarcoma who underwent surgical resection and received conventional adjuvant therapy.

The relationship between KRAS LCS6 polymorphism and endometrium cancer

The aim of this study was to investigate the relationship between KRAS LCS6 mutation and endometrial cancer (EC). The study included 105 patients who had hysterectomy for benign reasons and 99 EC patients. The patients with Type 1 EC were classified according to histological properties, cancer stage, grade, tumour dimension, myometrial invasion (MMI), lymphovascular invasion (LVI), cytology, and number of positive lymph nodes. KRAS LCS6 mutation was examined in blood samples taken from all patients in both groups. No statistically significant difference was determined between the EC patients and the control group in demographic features. Weight and the Body Mass Index (BMI) values were higher in EC group (p < .001). While the incidence of this polymorphism is 5.8% throughout the world, the polymorphism rate was found to be 16.2% in the EC group and 12.4% in the control group, with no statistically significant difference determined (p > .05). Despite the higher rate of LCS6 polymorphism incidence in EC patients in this study conducted on a relatively large sample, there was not found to be a statistically significant difference in comparison with the control group. In addition, the presence of LCS6 polymorphism was not determined to have an effect on EC histopathological characteristics.Impact statementWhat is already known on this subject? Endometrial cancer (EC) is a genital system cancer which is one of the most widespread gynecological cancers seen in the USA and other developed countries, In EC, the most frequently seen gene mutations are PTEN tumour suppressor gene, KRAS, β1 catenin, BCL-2, CTNNB and P53 mutations. KRAS LCS6(let-7 miRNA binding region polymorphism) polymorphism has a worldwide incidence of 5.8% (Chin et al. 2008).There are studies shown that KRAS LCS6 polymorphism has an effect on developing EC (Lee et al. 2014), ovarian cancer(Ratner et al. 2010)and endometriosis in women (Grechukhina et al. 2012).What do the results of this study add? In our study, LCS6 located on KRAS 3'-UTR was found at the rate of 16.2% in Type 1 EC patients. This increase is noticeable when it is considered that the incidence of this polymorphism is 5.8% in the general population. The results of the current study supports the preliminary findings of Lee et al.What are the implications of these findings for clinical practice and/or further research? These new genetic markers could help to develop gene-targeted therapies, identify genetic basis of the disease and the factors that could affect the EC prognosis.

Progression inference for somatic mutations in cancer

Computational methods were employed to determine progression inference of genomic alterations in commonly occurring cancers. Using cross-sectional TCGA data, we computed evolutionary trajectories involving selectivity relationships among pairs of gene-specific genomic alterations such as somatic mutations, deletions, amplifications, downregulation, and upregulation among the top 20 driver genes associated with each cancer. Results indicate that the majority of hierarchies involved TP53, PIK3CA, ERBB2, APC, KRAS, EGFR, IDH1, VHL, etc. Research into the order and accumulation of genomic alterations among cancer driver genes will ever-increase as the costs of nextgen sequencing subside, and personalized/precision medicine incorporates whole-genome scans into the diagnosis and treatment of cancer.

The Role of Serum MicroRNA-6767-5p as a Biomarker for the Diagnosis of Polycystic Ovary Syndrome

Background

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder, and the underlying molecular mechanisms are not clear. To date, few studies have been conducted on the altered expression of serum microRNAs (miRNAs) in women with PCOS. The present study was performed to examine the role of the serum miRNA as a biomarker for the diagnosis of PCOS and its relationship with metabolic and reproductive traits.

Methods

A cross-sectional comparison was made in 21 women with PCOS and age- and body mass index (BMI)- matched 21 healthy women in an academic center laboratory between December 2008 and October 2010. We selected miRNAs that were more than 1.5-fold up-regulated or less than 0.67-fold down-regulated in women with PCOS compared with controls using the SurePrint G3 Human miRNA Microarray. Subsequently, we validated the relative expression of the miRNAs using TaqMan quantitative real-time polymerase chain reaction (RT-qPCR) assays.

Results

Serum miRNA-4522, miRNA-324-3p, and miRNA-6767-5p were down-regulated in women with PCOS compared with controls in the microarray analysis. Among these miRNAs, serum miRNA-6767-5p was validated (fold change in women with PCOS/controls = 0.39, P-value<0.05) by RT-qPCR. The miRNA-6767-5p was negatively associated with fasting glucose (β = -0.370) and positively associated with the number of menses per year (β = 0.383) after adjustment for age and BMI (Ps<0.05). Genes targeted by miRNA-6767-5p were involved in the cell cycle and the immune system.

Conclusions

Serum miRNA-6767-5p may be a novel candidate as a molecular biomarker in the diagnosis of PCOS and may participate in the development of the metabolic and reproductive traits of PCOS.

FOXP1 forkhead transcription factor is associated with the pathogenesis of endometrial cancer

Endometrial cancers are mostly estrogen-dependent. FOXP1 is a P subfamily of forkhead box (FOX), and known as an estrogen-responsive transcription factor. The aims of this study were to examine histological location of FOXP1 in normal and malignant endometrium, and to investigate a possible association between FOXP1 and other factors considered to be involved in pathogenesis of endometrial cancer. The levels of FOXP1, estrogen receptor (ER)α, and ERβ expression were examined immunohistochemically in normal and malignant endometrium obtained from 75 women (8 normal, 8 atypical endometrial hyperplasia, and 59 endometrial cancers from grade 1 to 3). The effects of estrogen on ERα, FOXP1, KRAS, and PTEN expression were analyzed in telomerase-immortalized human endometrial stromal cells (T HESCs) by Western blotting. Western blotting was also used to examine the effect of FOXP1 plasmid DNA or siRNA transfection on KRAS and PTEN expression in Ishikawa cells (well differentiated endometrioid adenocarcinoma), HEC-50B cells (poorly differentiated endometrioid adenocarcinoma), and T HESCs, respectively. FOXP1 was expressed in normal and malignant endometrium, but the rate of expression was different depending upon menstrual cycle and pathological grade of malignancy. FOXP1 expression in nucleus and cytoplasm of grade 3 endometrioid cancers was significantly lower than that of grade 1 and 2 ones. Estradiol increased levels of FOXP1 and KRAS expression in a dose- and time-dependent manner in T HESCs cells, and FOXP1 transfection or knockdown led to increase or decrease of KRAS expression but not PTEN. KRAS expression level was significantly related to FOXP1 and ERα levels in cancer tissues. Estradiol did not affect KRAS expression in T HESCs cells transfected with FOXP1 siRNA. These results suggest that FOXP1 is involved in estrogen dependent endometrial cancers through KRAS pathway.

MicroRNAs in Cancer: A Historical Perspective on the Path from Discovery to Therapy

Recent progress in microRNA (miRNA) therapeutics has been strongly dependent on multiple seminal discoveries in the area of miRNA biology during the past two decades. In this review, we focus on the historical discoveries that collectively led to transitioning miRNAs into the clinic. We highlight the pivotal studies that identified the first miRNAs in Caenorhabditis elegans to the more recent reports that have fueled the quest to understand the use of miRNAs as markers for cancer diagnosis and prognosis. In addition, we provide insights as to how unraveling basic miRNA biology has provided a solid foundation for advancing miRNAs, such as miR-34a, therapeutically. We conclude with a brief examination of the current challenges that still need to be addressed to accelerate the path of miRNAs to the clinic: including delivery vehicles, miRNA- and delivery-associated toxicity, dosage, and off target effects.

Evaluation of KRAS Gene Expression and LCS6 Variant in Genomic and Cell-Free DNA of Iranian Women With Endometriosis

Since the activation of KRAS results in de novo endometriosis in mice, KRAS is regarded as a crucial gene in ectopic endometrial implantation. Recently, it has been reported that 31% of women with endometriosis have KRAS let-7 complementary binding site 6 single-nucleotide polymorphism (LCS6 SNP). This study addresses the correlation between KRAS LCS6 SNP and endometriosis in a case-control study. To detect probable somatic mutation in ectopic endometrial tissue, we evaluated LCS6 SNP in cell-free DNA samples. Quantitative real-time reverse transcription-polymerase chain reaction was performed to determine the expression of KRAS transcripts in eutopic endometrial tissue. Our results suggest that the variant is not associated with the development of endometriosis in Iranian women. We observed higher levels of KRAS messenger RNA (mRNA) expression in eutopic endometrium of patients with endometriosis compared to controls. Although, the KRAS LCS6 is neither constitutional nor somatic biomarker for endometriosis, increased expression ratio of KRAS mRNA indicates its role in the implantation of endometrial tissue outside the uterine cavity.

Estrogen withdrawal, increased breast cancer risk and the KRAS-variant

The KRAS-variant is a biologically functional, microRNA binding site variant, which predicts increased cancer risk especially for women. Because external exposures, such as chemotherapy, differentially impact the effect of this mutation, we evaluated the association of estrogen exposures, breast cancer (BC) risk and tumor biology in women with the KRAS-variant. Women with BC (n = 1712), the subset with the KRAS-variant (n = 286) and KRAS-variant unaffected controls (n = 80) were evaluated, and hormonal exposures, KRAS-variant status, and pathology were compared. The impact of estrogen withdrawal on transformation of isogenic normal breast cell lines with or without the KRAS-variant was studied. Finally, the association and presentation characteristics of the KRAS-variant and multiple primary breast cancer (MPBC) were evaluated. KRAS-variant BC patients were more likely to have ovarian removal pre-BC diagnosis than non-variant BC patients (p = 0.033). In addition, KRAS-variant BC patients also appeared to have a lower estrogen state than KRAS-variant unaffected controls, with a lower BMI (P < 0.001). Finally, hormone replacement therapy (HRT) discontinuation in KRAS-variant patients was associated with a diagnosis of triple negative BC (P < 0.001). Biologically confirming our clinical findings, acute estrogen withdrawal led to oncogenic transformation in KRAS-variant positive isogenic cell lines. Finally, KRAS-variant BC patients had greater than an 11-fold increased risk of presenting with MPBC compared to non-variant patients (45.39% vs 6.78%, OR 11.44 [3.42–37.87], P < 0.001). Thus, estrogen withdrawal and a low estrogen state appear to increase BC risk and to predict aggressive tumor biology in women with the KRAS-variant, who are also significantly more likely to present with multiple primary breast cancer.

MicroRNAS in endometrial cancer: recent advances and potential clinical applications

Endometrial cancer is a common malignant gynecological tumor, but there are few biomarkers that are useful for early and accurate diagnosis and few treatments other than surgery. However, use of microRNAs (miRNAs) that induces gene downregulation in cells may permit effective and minimally invasive diagnosis and treatment. In endometrial cancer cells, expression levels of miRNAs including miR-185, miR-210 and miR-423 are upregulated and those of miR-let7e, miR-30c and miR-221 are downregulated compared to normal tissues, and these miRNAs are involved in carcinogenesis, invasion and metastasis. miRNAs with expression changes such as miR-181b, miR-324-3p and miR-518b may be used as prognostic biomarkers and transfection of miR-152 may inhibit cancer growth. However, most current studies of miRNAs are at a basic level and further work is needed to establish clinical applications targeting miRNAs.

MicroRNA-mediated regulation of KRAS in cancer

While microRNAs (miRNAs) and the KRAS oncogene are known to be dysregulated in various cancers, little is known about the role of miRNAs in the regulation of KRAS in cancer. Here we review a selection of studies published in 2014 that have contributed to our understanding of the molecular mechanisms of KRAS regulation by miRNAs and the clinical relevance of sequence variants that may interfere with functional miRNA-mediated KRAS regulation.