Changes in cell proliferative parameters of SCCVII and EMT6 murine tumors after single-dose irradiation

The survival benefit of intensified full-dose XELOX chemotherapy concomitant to radiotherapy and then resting-period consolidation chemotherapy in locally advanced rectal cancer

Purpose: To evaluate the effect of an intensified capecitabine and oxaliplatin (XELOX) chemoradiation treatment followed by one cycle of consolidation chemotherapy before surgery in locally advanced rectal cancer (LARC).

Methods and Materials: Patients with histologically confirmed, newly diagnosed, locally advanced rectal adenocarcinoma (cT3-T4 and/or cN+) were enrolled. All patients received 3-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) with a dose 50.4Gy in 25 fraction, with two cycles of concurrent XELOX chemotherapy. Thereafter, another cycle of consolidation chemotherapy with XELOX/FLOFOX was administered during the resting period after completion of concurrent chemoradiation (CRT). Tumor response, toxicities, surgical complications, and long-term clinical outcomes were recorded.

Results: From January 2011 to December 2013, a total of 96 patients were enrolled in the study. All patients completed the treatment plan of concurrent chemoradiation and consolidate chemotherapy. During concurrent chemoradiation, the incidence of grade 3/4 toxicities was leucopenia (2.1%), thrombocytopenia (4.2%), diarrhea (6.3%). 18 patients (18.8%) developed surgical complications. Pathologic complete response (pCR) was achieved in 20 (20.8%) patients. Tumor down-staging occurred in 69 (71.9%) patients and down-staging of nodes occurred in 47 (49.0%) patients. Of these 96 patients, 5-year local recurrence-free survival, metastasis-free survival, disease-free survival and overall survival rates was 98.9%, 84.7%, 83.7% and 82.1%, respectively, with a median follow-up of 4.24years.

Conclusions: The intensified treatment paradigm of XELOX concurrent chemoradiation followed by one cycle of consolidation chemotherapy was well tolerated in our cohort and provided a promising long-term oncologic outcome, which warranted further investigation in a randomize trails.

Modeling of the metabolic energy dissipation for restricted tumor growth

Energy dissipation mostly represents unwanted outcome but in the biochemical processes it may alter the biochemical pathways. However, it is rarely considered in the literature although energy dissipation and its alteration due to the changes in cell microenvironment may improve methods for guiding chemical and biochemical processes in the desired directions. Deeper insight into the changes of metabolic activity of tumor cells exposed to osmotic stress or irradiation may offer the possibility of tumor growth reduction. In this work effects of the osmotic stress and irradiation on the thermodynamical affinity of tumor cells and their damping effects on metabolic energy dissipation were investigated and modeled. Although many various models were applied to consider the tumor restrictive growth they have not considered the metabolic energy dissipation. In this work a pseudo rheological model in the form of "the metabolic spring-pot element" is formulated to describe theoretically the metabolic susceptibility of tumor spheroid. This analog model relates the thermodynamical affinity of cell growth with the volume expansion of tumor spheroid under isotropic loading conditions. Spheroid relaxation induces anomalous nature of the metabolic energy dissipation which causes the damping effects on cell growth. The proposed model can be used for determining the metabolic energy "structure" in the context of restrictive cell growth as well as for predicting optimal doses for cancer curing in order to tailor the clinical treatment for each person and each type of cancer.

The influence of DNA ploidy of a human tumor cell line on the frequencies of micronuclei or chromosome aberrations after irradiation

To develop methods for assessing the intrinsic cellular radiosensitivity, it is important to evaluate the relationship between DNA ploidy of cells and frequencies of micronuclei (MN) or chromosome aberrations after irradiation. From the original human fibrosarcoma cell line HT-1080, we isolated two clones which have different chromosome ploidy: clone 5 is pseudodiploid and clone 1 is heteroploid. We examined the radiosensitivity of the two clones using a clonogenic cell survival assay and a cytokinesis-block MN assay, and by scoring chromosome aberrations using the premature chromosome condensation (PCC) method combined with a fluorescence in situ hybridization (FISH) procedure immediately and at 24 h after irradiation. The MN frequency increased according to the irradiation dose in both clones. The MN frequency of clone 1 was significantly higher than that of clone 5 regardless of whether the assay was performed immediately or 24 h after irradiation. However, when the numbers of MN were normalized by the DNA index of each clone, a significant difference in the frequency of MN was not observed. In the PCC and FISH studies, there was a linear relationship between the radiation dose and the initial breaks of chromosome 4, but the breaks of clone 1 were much more frequent than those of clone 5. Twenty-four h after irradiation, the chromosome 4 breaks of clone 1 were observed much more frequently than those of clone 5 at the same radiation dose. When the numbers of chromosome 4 breaks were normalized by the number of chromosome 4 in each clone without radiation, no such difference in the number of breaks was observed. These findings demonstrated that the DNA content or chromosome ploidy influenced the induction of the MN or chromosome aberrations in HT-1080 cells after irradiation.