Circulating lymphocyte number has a positive association with tumor response in neoadjuvant chemoradiotherapy for advanced rectal cancer

Although neoadjuvant chemoradiotherapy (CRT) is the standard treatment for advanced rectal cancer (RC), markers to predict the treatment response have not been fully established. In 73 patients with advanced RC who underwent CRT in a neoadjuvant setting, we retrospectively examined the associations between the clinical effects of CRT and blood cell counts before and after CRT. Clinical or pathological complete response (CR) was observed in 10 (14%) cases. The CR rate correlated significantly with the size and the circumferential extent of the tumor. Hemoglobin level, white blood cell (WBC) count and platelet count before CRT did not show a significant difference between CR and non-CR cases. Interestingly, however, lymphocyte ratio in WBC was significantly higher (p = 0.020), while neutrophil ratio tended to be lower (p = 0.099), in CR cases, which was shown to be an independent association by multivariate analysis. When all the blood data obtained in the entire treatment period were evaluated, circulating lymphocyte count was most markedly decreased in the CRT period and gradually recovered by the time of surgery, while the numbers of neutrophils and monocytes were comparatively stable. Moreover, the lymphocyte percentage in samples obtained from CR patients was maintained at a relatively higher level than that from non-CR patients. Since tumor shrinkage is known to be dependent not only on the characteristics of tumor cells but also on various host conditions, our data raise the possibility that a lymphocyte-mediated immune reaction may have a positive role in achieving complete eradication of tumor cells. Maintenance of circulating lymphocyte number may improve the response to CRT in rectal cancer

Microarray profiling of mononuclear peripheral blood cells identifies novle candidate genes related to chemoradiation response in rectal cancer

Preoperative chemoradiation significantly improves oncological outcome in locally advanced rectal cancer. However there is no effective method of predicting tumor response to chemoradiation in these patients. Peripheral blood mononuclear cells have emerged recently as pathology markers of cancer and other diseases, making possible their use as therapy predictors. Furthermore, the importance of the immune response in radiosensivity of solid organs led us to hypothesized that microarray gene expression profiling of peripheral blood mononuclear cells could identify patients with response to chemoradiation in rectal cancer. Thirty five 35 patients with locally advanced rectal cancer were recruited initially to perform the study. Peripheral blood samples were obtained before neaodjuvant treatment. RNA was extracted and purified to obtain cDNA and cRNA for hybridization of microarrays included in Human WG CodeLink bioarrays. Quantitative real time PCR was used to validate microarray experiment data. Results were correlated with pathological response, according to Mandard´s criteria and final UICC Stage (patients with tumor regression grade 1–2 and downstaging being defined as responders and patients with grade 3–5 and no downstaging as non-responders). Twenty seven out of 35 patients were finally included in the study. We performed a multiple t-test using Significance Analysis of Microarrays, to find those genes differing significantly in expression, between responders (n = 11) and non-responders (n = 16) to CRT. The differently expressed genes were: BC 035656.1, CIR, PRDM2, CAPG, FALZ, HLA-DPB2, NUPL2, and ZFP36. The measurement of FALZ (p = 0.029) gene expression level determined by qRT-PCR, showed statistically significant differences between the two groups. Gene expression profiling reveals novel genes in peripheral blood samples of mononuclear cells that could predict responders and non-responders to chemoradiation in patients with locally advanced rectal cancer. Moreover, our investigation added further evidence to the importance of mononuclear cells’ mediated response in the neoadjuvant treatment of rectal cancer.This investigation was supported by the Fundación Investigación Biomédica Mutua Madrileña. MC, CC and AB were supported by projects P08-TIC-4299 and CTS2200 of Junta de Andalucía, TIN2009-13489 of DGICT, Madrid, and GREIB PYR_2010-02 and 2010_05 of University of Granada

Early and late skin reactions to radiotherapy for breast cancer and their correlation with radiation-induced DNA damage in lymphocytes

INTRODUCTION: Radiotherapy outcomes might be further improved by a greater understanding of the individual variations in normal tissue reactions that determine tolerance. Most published studies on radiation toxicity have been performed retrospectively. Our prospective study was launched in 1996 to measure the in vitro radiosensitivity of peripheral blood lymphocytes before treatment with radical radiotherapy in patients with breast cancer, and to assess the early and the late radiation skin side effects in the same group of patients. We prospectively recruited consecutive breast cancer patients receiving radiation therapy after breast surgery. To evaluate whether early and late side effects of radiotherapy can be predicted by the assay, a study was conducted of the association between the results of in vitro radiosensitivity tests and acute and late adverse radiation effects. METHODS: Intrinsic molecular radiosensitivity was measured by using an initial radiation-induced DNA damage assay on lymphocytes obtained from breast cancer patients before radiotherapy. Acute reactions were assessed in 108 of these patients on the last treatment day. Late morbidity was assessed after 7 years of follow-up in some of these patients. The Radiation Therapy Oncology Group (RTOG) morbidity score system was used for both assessments. RESULTS: Radiosensitivity values obtained using the in vitro test showed no relation with the acute or late adverse skin reactions observed. There was no evidence of a relation between acute and late normal tissue reactions assessed in the same patients. A positive relation was found between the treatment volume and both early and late side effects. CONCLUSION: After radiation treatment, a number of cells containing major changes can have a long survival and disappear very slowly, becoming a chronic focus of immunological system stimulation. This stimulation can produce, in a stochastic manner, late radiation-related adverse effects of varying severity. Further research is warranted to identify the major determinants of normal tissue radiation response to make it possible to individualize treatments and improve the outcome of radiotherapy in cancer patients

The Ionizing Radiation-Induced Bystander Effect: Evidence, Mechanism, and Significance

It has long been considered that the important biological effects of ionizing radiation are a direct consequence of unrepaired or misrepaired DNA damage occurring in the irradiated cells. It was presumed that no effect would occur in cells in the population that receive no direct radiation exposure. However, in vitro evidence generated over the past two decades has indicated that non-targeted cells in irradiated cell cultures also experience significant biochemical and phenotypic changes that are often similar to those observed in the targeted cells. Further, nontargeted tissues in partial body-irradiated rodents also experienced stressful effects, including oxidative and oncogenic effects. This phenomenon, termed the “bystander response,” has been postulated to impact both the estimation of health risks of exposure to low doses/low fluences of ionizing radiation and the induction of second primary cancers following radiotherapy. Several mechanisms involving secreted soluble factors, oxidative metabolism, gap-junction intercellular communication, and DNA repair, have been proposed to regulate radiation-induced bystander effects. The latter mechanisms are major mediators of the system responses to ionizing radiation exposure, and our knowledge of the biochemical and molecular events involved in these processes is reviewed in this chapter

Pulsed field gel electrophoresis on single murine hemopoietic colonies.

We report a technique which allows for the direct molecular analysis of single whole murine hemopoietic colonies by pulsed field gel electrophoresis (PFGE). Murine bone marrow cells were plated out in semi-solid agarose and gave rise to macroscopic colonies after 11 days in culture. Single colonies were excised from the agarose using a sterile blade and embedded without further manipulation in molten low-melting-temperature agarose. The leucocyte DNA contained within the agarose plug was subjected to restriction enzyme digestion and PFGE. Sufficient high molecular weight DNA is afforded by this method to achieve a hybridization signal with a single copy probe. This method will make PFGE directly applicable to the clonal analysis of chromosomal aberrations in hemopoietic stem and progenitor cells