miRNAs are increasingly associated with the aggressive phenotype of prostate tumours. Their ability to control radiobiologically-relevant cellular processes strengthens their potential as novel ...markers of response to radiation therapy.
To identify miRNAs associated with increased clonogenic survival following radiation exposure.
The miRNA expression profiles of a panel of 22RV1 cells with varying levels of radiosensitivities (hypoxic H-22Rv1 cells, RR-22Rv1 cells derived from WT-22Rv1 cells through 2-Gy fractionated repeated exposure, the associated aged matched cells (AMC-22Rv1) and the WT-22Rv1 cell lines) were generated and cross-analysed to identify common miRNAs associated with a radioresistant phenotype.
Increased clonogenic survival following irradiation was associated with significant modifications in miRNA expression pattern. miR-221 (up) and miR-4284 (down) in RR-22Rv1 and MiR-31 and miR-200c in AMC-22Rv1 were the most uniquely significantly deregulated miRNAs when compared to WT-22Rv1 cells. miR-200c ranked as the most downregulated miRNAs in hypoxic, when compared to RR-22Rv1 cells. miR-200a was the only differentially expressed miRNA between RR-22Rv1 and AMC-22Rv1 cells. miR-210 yielded the highest fold change in expression in H-22Rv1, when compared to WT-22RV1 cells.
This study identifies candidate miRNAs for the development of novel prognostic biomarkers for radiotherapy prostate cancer patients.
Background: The sex-neutral language used in preclinical and clinical research intends to be inclusive of both the female and the male population, but the practice of data pooling prevents the ...detection of the impact of sex on cancer biology and response to medications and treatment. This study aimed to examine the consideration of sex as biological variable in the evaluation of radiation therapy in preclinical and clinical studies.
Methods: Preclinical and clinical studies published over a 12-month period were reviewed for the reporting of cells, animal or patient sex and the inclusion of sex as a biological variable in both study design and data analysis.
Results: A total of 321 articles met the inclusion criteria: 41 (13%) preclinical and 280 (87%) clinical studies. Two articles reported separate outcome data for males and females. Where the sex of participants was stated (230/280 (82%), 81% reported a larger number of male participants, compared to females. Less than half (45%) of studies used sex as a variable in data analysis. Sex disparity was not dependent on study location but may be more prominent in certain cancer sites. In preclinical studies, sex was at best stated in those reporting on animals (48% of studies).
Conclusion: Referring to a radiotherapy cancer patient, the literature is female inclusive, but a gap does exist when it comes to consideration of sex in data analysis. The pooled analysis of female and male data could introduce statistical biases and prevent the identification of key sex-specific biological subtilities that do affect radiation responses.
MicroRNAs (miRNAs) are an abundant class of noncoding RNAs that function to regulate post-transcriptional gene expression, predominantly by translational repression. In addition to their role in ...prostate cancer initiation and progression, recent evidence suggests that miRNAs might also participate in treatment response across a range of therapies including radiation treatment, chemotherapy and androgen suppression. The mechanism of this regulation is thought to be multifactorial and is currently poorly understood. To date, only a small number of studies have examined the functional role of miRNAs in response to prostate cancer treatment. Elucidating the role of miRNAs in treatment response following radiotherapy, chemotherapy and androgen suppression will provide new avenues of investigation for the development of novel therapies for the treatment of prostate cancer.
The Notch-3 receptor is a recognized key regulator of vascular responses and is increasingly associated with tumorigenesis. Hypoxia-inducible factors activate specific signaling pathways such as ...Notch in a number of cellular models. This study aimed to evaluate the regulation of Notch-3 by hypoxia in prostate cancer cells. Notch-3 gene and protein expression was established in a panel of aerobic and hypoxic prostate cell lines in vitro, the CWR22 xenograft model and RNA extracted from low grade (Gleason score < = 6); high grade (Gleason score > = 7); non-hypoxic (low HIF, low VEGF); hypoxic (high HIF, high VEGF) patient FFPE specimens. NOTCH-3 was upregulated in PC3 (3-fold), 22Rv1 (4.1-fold) and DU145 (3.8-fold) but downregulated in LnCaP (12-fold) compared to the normal cell lines. NOTCH-3 expression was modified following hypoxic exposure in these cells. NOTCH-3 was upregulated (2.2-fold) in higher grade and hypoxic tumors, when compared to benign and aerobic pools. In the CWR22 xenograft model, Notch-3 expression was restored in castrate resistant tumors. Nuclear translocation of the Notch-3 intracellular domain was no longer detected following exposure of cells to hypoxia but not associated with a change in expression of HES-1. Our data further identifies Notch-3 as a potentially key hypoxic-responsive member of the Notch pathway in prostate tumorigenesis.
Prostate cancer is among the most prevalent life-threatening cancers diagnosed in the male population today. Various methods have been exploited in an attempt to treat this disease but these ...treatments, alongside preventative tactics, have been insufficient to control mortality rates and have usually resulted in detrimental adverse events. An opportunity to devise more-specific and potentially more-effective approaches for the eradication of prostate tumours can be found by targeting specific biological pathways. NUMB (protein numb homologue), a key regulator of cell fate, represents an attractive, actionable target in prostate cancer. NUMB participates in the observed deregulation of NOTCH (neurogenic locus notch homologue protein) signalling in prostate tumours, and the NUMB-NOTCH interaction regulates cell fate. NUMB has potential both as a target for control of prostate tumorigenesis and as a biomarker for identification of patients with prostate cancer who are likely to benefit from NOTCH inhibition.
Abstract
Purpose: The comparison of cell lines with differing radiosensitivities and their molecular response to radiation exposure has been used in a number of human cancer models to study the ...molecular response to radiation. This review proposes to analyze and compare the protocols used by investigators for the development and validation of these isogenic models of radioresistance.
Conclusion: There is large variability in the strategies used to generate and validate isogenic models of radioresistance. Further characterization of these models is required.
Summary
In this single centre study of childhood acute lymphoblastic leukaemia (ALL) patients treated on the Medical Research Council UKALL 97/99 protocols, it was determined that minimal residual ...disease (MRD) detected by real time quantitative polymerase chain reaction (RQ‐PCR) and 3‐colour flow cytometry (FC) displayed high levels of qualitative concordance when evaluated at multiple time‐points during treatment (93·38%), and a combined use of both approaches allowed a multi time‐point evaluation of MRD kinetics for 90% (53/59) of the initial cohort. At diagnosis, MRD markers with sensitivity of at least 0·01% were identified by RQ‐PCR detection of fusion gene transcripts, IGH/TRG rearrangements, and FC. Using a combined RQ‐PCR and FC approach, the evaluation of 367 follow‐up BM samples revealed that the detection of MRD >1% at Day 15 (P = 0·04), >0·01% at the end of induction (P = 0·02), >0·01% at the end of consolidation (P = 0·01), >0·01% prior to the first delayed intensification (P = 0·01), and >0·1% prior to the second delayed intensification and continued maintenance (P = 0·001) were all associated with relapse and, based on early time‐points (end of induction and consolidation) a significant log‐rank trend (P = 0·0091) was noted between survival curves for patients stratified into high, intermediate and low‐risk MRD groups.
Gemcitabine is indicated in combination with cisplatin as first-line therapy for solid tumours including non-small cell lung cancer (NSCLC), bladder cancer and mesothelioma. Gemcitabine is an ...analogue of pyrimidine cytosine and functions as an anti-metabolite. Structurally, however, gemcitabine has similarities to 5-aza-2-deoxycytidine (decitabine/Dacogen®), a DNA methyltransferase inhibitor (DNMTi). NSCLC, mesothelioma and prostate cancer cell lines were treated with decitabine and gemcitabine. Reactivation of epigenetically silenced genes was examined by RT-PCR/qPCR. DNA methyltransferase activity in nuclear extracts and recombinant proteins was measured using a DNA methyl-transferase assay, and alterations in DNA methylation status were examined using methylation-specific PCR (MS-PCR) and pyrosequencing. We observe a reactivation of several epigenetically silenced genes including GSTP1, IGFBP3 and RASSF1A. Gemcitabine functionally inhibited DNA methyltransferase activity in both nuclear extracts and recombinant proteins. Gemcitabine dramatically destabilised DNMT1 protein. However, DNA CpG methylation was for the most part unaffected by gemcitabine. In conclusion, gemcitabine both inhibits and destabilises DNA methyltransferases and reactivates epigenetically silenced genes having activity equivalent to decitabine at concentrations significantly lower than those achieved in the treatment of patients with solid tumours. This property may contribute to the anticancer activity of gemcitabine.
PDF
