Chromosomal instability as a prognostic marker in cervical cancer.

BACKGROUND: Cervical cancer is the third most common cancer in women globally, and despite treatment, distant metastasis and nodal recurrence will still develop in approximately 30% of patients. The ability to predict which patients are likely to experience distant relapse would allow clinicians to better tailor treatment. Previous studies have investigated the role of chromosomal instability (CIN) in cancer, which can promote tumour initiation and growth; a hallmark of human malignancies. In this study, we sought to examine the published CIN70 gene signature in a cohort of cervical cancer patients treated at the Princess Margaret (PM) Cancer Centre and an independent cohort of The Cancer Genome Atlas (TCGA) cervical cancer patients, to determine if this CIN signature associated with patient outcome. METHODS: Cervical cancer samples were collected from 79 patients, treated between 2000-2007 at the PM, prior to undergoing curative chemo-radiation. Total RNA was extracted from each patient sample and analyzed using the GeneChip Human Genome U133 Plus 2.0 array (Affymetrix). RESULTS: High CIN70 scores were significantly related to increased chromosomal alterations in TCGA cervical cancer patients, including a higher percentage of genome altered and a higher number of copy number alterations. In addition, this same CIN70 signature was shown to be predictive of para-aortic nodal relapse in the PM Cancer Centre cohort. CONCLUSIONS: These findings demonstrate that chromosomal instability plays an important role in cervical cancer, and is significantly associated with patient outcome. For the first time, this CIN70 gene signature provided prognostic value for patients with cervical cancer.

Developing a prognostic micro-RNA signature for human cervical carcinoma.

Cervical cancer remains the third most frequently diagnosed and fourth leading cause of cancer death in women worldwide. We sought to develop a micro-RNA signature that was prognostic for disease-free survival, which could potentially allow tailoring of treatment for cervical cancer patients. A candidate prognostic 9-micro-RNA signature set was identified in the training set of 79 frozen specimens. However, three different approaches to validate this signature in an independent cohort of 87 patients with formalin-fixed paraffin-embedded (FFPE) specimens, were unsuccessful. There are several challenges and considerations associated with developing a prognostic micro-RNA signature for cervical cancer, namely: tumour heterogeneity, lack of concordance between frozen and FFPE specimens, and platform selection for global micro-RNA expression profiling in this disease. Our observations provide an important cautionary tale for future miRNA signature studies for cervical cancer, which can also be potentially applicable to miRNA profiling studies involving other types of human malignancies.

The microRNA-218~Survivin axis regulates migration, invasion, and lymph node metastasis in cervical cancer.

Cervical cancer is the third most common cancer in women worldwide. In the present study, global microRNA profiling for 79 cervical cancer patient samples led to the identification of miR-218 down-regulation in cervical cancer tissues compared to normal cervical tissues. Lower miR-218 expression was associated significantly with worse overall survival (OS), disease-free survival (DFS), and pelvic/aortic lymph node recurrence. In vitro, miR-218 over-expression decreased clonogenicity, migration, and invasion. Survivin (BIRC5) was subsequently identified as an important cervical cancer target of miR-218 using in silico prediction, mRNA profiling, and quantitative real-time PCR (qRT-PCR). Concordant with miR-218 over-expression, survivin knockdown by siRNA decreased clonogenicity, migration, and invasion. YM155, a small molecule survivin inhibitor, significantly suppressed tumor growth and lymph node metastasis in vivo. Our findings demonstrate that the miR-218~survivin axis inhibits cervical cancer progression by regulating clonogenicity, migration, and invasion, and suggest that the inhibition of survivin could be a potential therapeutic strategy to improve outcome in this disease.

Hotspot activating PRKD1 somatic mutations in polymorphous low-grade adenocarcinomas of the salivary glands.

Polymorphous low-grade adenocarcinoma (PLGA) is the second most frequent type of malignant tumor of the minor salivary glands. We identified PRKD1 hotspot mutations encoding p.Glu710Asp in 72.9% of PLGAs but not in other salivary gland tumors. Functional studies demonstrated that this kinase-activating alteration likely constitutes a driver of PLGA.

Novel PRKD gene rearrangements and variant fusions in cribriform adenocarcinoma of salivary gland origin.

Polymorphous low-grade adenocarcinoma (PLGA) and cribriform adenocarcinoma of minor salivary gland (CAMSG) are low-grade carcinomas arising most often in oral cavity and oropharynx, respectively. Controversy exists as to whether these tumors represent separate entities or variants of one spectrum, as they appear to have significant overlap, but also clinicopathologic differences. As many salivary carcinomas harbor recurrent translocations, paired-end RNA sequencing and FusionSeq data analysis was applied for novel fusion discovery on two CAMSGs and two PLGAs. Validated rearrangements were then screened by fluorescence in situ hybridization (FISH) in 60 cases. Histologic classification was performed without knowledge of fusion status and included: 21 CAMSG, 18 classic PLGA, and 21 with "mixed/indeterminate" features. The RNAseq of 2 CAMSGs showed ARID1A-PRKD1 and DDX3X-PRKD1 fusions, respectively, while no fusion candidates were identified in two PLGAs. FISH for PRKD1 rearrangements identified 11 additional cases (22%), two more showing ARID1A-PRKD1 fusions. As PRKD2 and PRKD3 share similar functions with PRKD1 in the diacylglycerol and protein kinase C signal transduction pathway, we expanded the investigation for these genes by FISH. Six additional cases each showed PRKD2 and PRKD3 rearrangements. Of the 26 (43%) fusion-positive tumors, there were 16 (80%) CAMSGs and 9 (45%) indeterminate cases. A PRKD2 rearrangement was detected in one PLGA (6%). We describe novel and recurrent gene rearrangements in PRKD1-3 primarily in CAMSG, suggesting a possible pathogenetic dichotomy from "classic" PLGA. However, the presence of similar genetic findings in half of the indeterminate cases and a single PLGA suggests a possible shared pathogenesis for these tumor types.

MicroRNA-196b regulates the homeobox B7-vascular endothelial growth factor axis in cervical cancer.

The down-regulation of microRNA-196b (miR-196b) has been reported, but its contribution to cervical cancer progression remains to be investigated. In this study, we first demonstrated that miR-196b down-regulation was significantly associated with worse disease-free survival (DFS) for cervical cancer patients treated with combined chemo-radiation. Secondly, using a tri-modal approach for target identification, we determined that homeobox-B7 (HOXB7) was a bona fide target for miR-196b, and in turn, vascular endothelial growth factor (VEGF) was a downstream transcript regulated by HOXB7. Reconstitution of miR-196b expression by transient transfection resulted in reduced cell growth, clonogenicity, migration and invasion in vitro, as well as reduced tumor angiogenesis and tumor cell proliferation in vivo. Concordantly, siRNA knockdown of HOXB7 or VEGF phenocopied the biological effects of miR-196b over-expression. Our findings have demonstrated that the miR-196b/HOXB7/VEGF pathway plays an important role in cervical cancer progression; hence targeting this pathway could be a promising therapeutic strategy for the future management of this disease.

Excellence in Radiation Research for the 21st Century (EIRR21): description of an innovative research training program.

PURPOSE: To describe and assess an interdisciplinary research training program for graduate students, postdoctoral fellows, and clinical fellows focused on radiation medicine; funded by the Canadian Institutes for Health Research since 2003, the program entitled "Excellence in Radiation Research for the 21st Century" (EIRR21) aims to train the next generation of interdisciplinary radiation medicine researchers. METHODS AND MATERIALS: Online surveys evaluating EIRR21 were sent to trainees (n=56), mentors (n=36), and seminar speakers (n=72). Face-to-face interviews were also conducted for trainee liaisons (n=4) and participants in the international exchange program (n=2). RESULTS: Overall response rates ranged from 53% (mentors) to 91% (trainees). EIRR21 was well received by trainees, with the acquisition of several important skills related to their research endeavors. An innovative seminar series, entitled Brainstorm sessions, imparting "extracurricular" knowledge in intellectual property protection, commercialization strategies, and effective communication, was considered to be the most valuable component of the program. Networking with researchers in other disciplines was also facilitated owing to program participation. CONCLUSIONS: EIRR21 is an innovative training program that positively impacts the biomedical community and imparts valuable skill sets to foster success for the future generation of radiation medicine researchers.

Micro-RNAs as diagnostic or prognostic markers in human epithelial malignancies.

Micro-RNAs (miRs) are important regulators of mRNA and protein expression; the ability of miR expression profilings to distinguish different cancer types and classify their sub-types has been well-described. They also represent a novel biological entity with potential value as tumour biomarkers, which can improve diagnosis, prognosis, and monitoring of treatment response for human cancers. This endeavour has been greatly facilitated by the stability of miRs in formalin-fixed paraffin-embedded (FFPE) tissues, and their detection in circulation. This review will summarize some of the key dysregulated miRs described to date in human epithelial malignancies, and their potential value as molecular bio-markers in FFPE tissues and blood samples. There remain many challenges in this domain, however, with the evolution of different platforms, the complexities of normalizing miR profiling data, and the importance of evaluating sufficiently-powered training and validation cohorts. Nonetheless, well-conducted miR profiling studies should contribute important insights into the molecular aberrations driving human cancer development and progression.

The effect of cytotoxic chemotherapy on female fertility.

Nurses are now primarily responsible for the provision of patient information, and the administration of an escalating number of cytotoxic agents. This paper aims to provide nurses with key information concerning the adverse effects of cytotoxic chemotherapy on the reproductive system of women of childbearing age. The provision of information on gonadal function and fertility is vital, particularly with the increase in the survival of women treated for cancer, and the trend towards women starting a family later in life. Gonadal toxicity of the various cytotoxic agents, disruption of the menstrual cycle, premature menopause, avoidance of pregnancy, chemotherapy in pregnancy, and fertility prospects post-chemotherapy are addressed in this paper.