Strain-dependent damage in mouse lung after carbon ion irradiation.

PURPOSE: To examine whether inherent factors produce differences in lung morbidity in response to carbon ion (C-ion) irradiation, and to identify the molecules that have a key role in strain-dependent adverse effects in the lung. METHODS AND MATERIALS: Three strains of female mice (C3H/He Slc, C57BL/6J Jms Slc, and A/J Jms Slc) were locally irradiated in the thorax with either C-ion beams (290 MeV/n, in 6 cm spread-out Bragg peak) or with ¹³7Cs γ-rays as a reference beam. We performed survival assays and histologic examination of the lung with hematoxylin-eosin and Masson's trichrome staining. In addition, we performed immunohistochemical staining for hyaluronic acid (HA), CD44, and Mac3 and assayed for gene expression. RESULTS: The survival data in mice showed a between-strain variance after C-ion irradiation with 10 Gy. The median survival time of C3H/He was significantly shortened after C-ion irradiation at the higher dose of 12.5 Gy. Histologic examination revealed early-phase hemorrhagic pneumonitis in C3H/He and late-phase focal fibrotic lesions in C57BL/6J after C-ion irradiation with 10 Gy. Pleural effusion was apparent in C57BL/6J and A/J mice, 168 days after C-ion irradiation with 10 Gy. Microarray analysis of irradiated lung tissue in the three mouse strains identified differential expression changes in growth differentiation factor 15 (Gdf15), which regulates macrophage function, and hyaluronan synthase 1 (Has1), which plays a role in HA metabolism. Immunohistochemistry showed that the number of CD44-positive cells, a surrogate marker for HA accumulation, and Mac3-positive cells, a marker for macrophage infiltration in irradiated lung, varied significantly among the three mouse strains during the early phase. CONCLUSIONS: This study demonstrated a strain-dependent differential response in mice to C-ion thoracic irradiation. Our findings identified candidate molecules that could be implicated in the between-strain variance to early hemorrhagic pneumonitis after C-ion irradiation.

Combination effects of distinct cores in 11q13 amplification region on cervical lymph node metastasis of oral squamous cell carcinoma.

Lymph node metastasis (LNM) in oral squamous cell carcinoma (OSCC) is known to associate with a significant decrease of 5-year survival. Genetic factors related to the difference of the LNM status in the OSCC have been not fully elucidated. Array-based comparative genomic hybridization (CGH) with individual gene-level resolution and real-time quantitative polymerase chain reaction (QPCR) were conducted using primary tumor materials resected from 54 OSCC patients with (n=22) or without (n=32) cervical LNM. Frequent gain was observed at the 11q13 region exclusively in patients with cervical LNM, which was confirmed by real-time QPCR experiments using 11 genes (TPCN2, MYEOV, CCND1, ORAOV1, FGF4, TMEM16A, FADD, PPFIA1, CTTN, SHANK2 and DHCR7) in this region. It was revealed that two distinct amplification cores existed, which were separated by a breakpoint between MYEOV and CCND1 in the 11q13 region. The combination of copy number amplification at CTTN (core 2) and/or TPCN2/MYEOV (core 1), selected from each core, was most significantly associated with cervical LNM (P=0.0035). Two amplification cores at the 11q13 region may have biological impacts on OSCC cells to spread from the primary site to local lymph nodes. Further study of a larger patient series should be conducted to validate these results.

Attenuated lung fibrosis in interleukin 6 knock-out mice after C-ion irradiation to lung.

There is a great deal of evidence that a cyclic cascade of inflammatory cytokines, together with the activation of macrophages, is initiated very early after irradiation to develop lung fibrosis in a late phase. To understand the persistent effects of cytokines, the cytokine gene of knock out or transgenic mouse is one of the useful tools. In this study, we evaluated a role of a key molecule, interleukin-6 (IL-6), in the late-phase inflammatory response and subsequent fibrotic changes after irradiation using wild-type (WT) and IL-6 knock out (IL-6 KO) mice. The mice underwent thoracic irradiation with 10 Gy of C-ion beam or sham-irradiation and were examined by histology. Immunoreactivity for IL-6 was induced at the site of bronchiolar epithelium, in pneumocytes and in monocytes by C-ion irradiation. At 24 weeks after irradiation, the infiltration of macrophages, detected by positive immunohistological staining with Mac3 antibody, was observed in alveolar spaces both in WT and IL-6 KO mice. The thickening of bronchiolar and alveolar walls exhibited in WT mice, but not KO mice, and fibrotic changes detected by Masson-Trichrome staining, were observed only in the lungs of WT mice, while it was attenuated in IL-6 KO mice. These results indicated that IL-6 might not be essential for activating macrophages in the late phase, but plays an important role for fibrotic changes of the alveolar wall after irradiation.

Villin1, a diagnostic marker for endometrial adenocarcinoma with high grade nuclear atypia.

Villin1 (VIL1) has a role in regulating actin dynamics, cell morphology, anti-apoptotic mechanisms, and epithelial-to-mesenchymal transition. Previously we reported VIL1 as a novel diagnostic marker for cervical adenocarcinoma (AC) with poor radioresponse. This study further investigated the diagnostic role of VIL1 in gynecological tumors especially endometrial AC. We recruited 107 patients with AC (41 tumors in the corpus and 66 tumors in cervix), most of whom treated by total abdominal hysterectomy. Immunohistochemical analysis revealed VIL1-positive tumors in 37% of cases; 10 of 41 corpus tumors and 30 of 66 tumors in the cervix. VIL1-positive tumors were further examined histologically and immunostained for epithelial cell surface marker, EpCAM, and mesenchymal stem cell marker, CD44. Most of these tumors were CD44 negative and EpCAM positive, and the cytoplasmic VIL1 immunoreactivity in endometrial AC was more selective than EpCAM in reflecting histological aggressiveness with high grade nuclear atypia. This study confirmed our previous finding of VIL1 as a diagnostic marker of cervical AC. In addition, VIL1 immunostaining was detected in 25% of endometrial AC cases. These results suggested the existence of an aggressive and VIL1-positive subtype of gynecological tumor.

X-ray irradiation and Rho-kinase inhibitor additively induce invasiveness of the cells of the pancreatic cancer line, MIAPaCa-2, which exhibits mesenchymal and amoeboid motility.

Tumor cells can migrate and invade tissue by two modes of motility: mesenchymal and amoeboid. X-ray or γ-ray irradiation increases the invasiveness of tumor cells with mesenchymal motility through the induction of matrix metalloproteinases (MMP), and this increase is suppressed by MMP inhibitors (MMPI). However, the effects of X-ray or γ-ray irradiation on the invasiveness of tumor cells with amoeboid motility remain unclear. We investigated the effect of irradiation on amoeboid motility by using cells of the human pancreatic cancer line, MIAPaCa-2, which exhibits both modes of motility. The X-ray-induced invasiveness of MIAPaCa-2 cells was associated with the upregulation of MMP2 at both the RNA and protein levels and was inhibited by MMPI treatment. Amoeboid-mesenchymal transition was slightly induced after irradiation. The MMPI treatment caused mesenchymal-amoeboid transition without significant increase in invasiveness, while the ROCK inhibitor (ROCKI) stimulated amoeboid-mesenchymal transition and enhanced invasiveness under both non-irradiated and irradiated conditions. This ROCKI-induced transition was accompanied by the upregulation of MMP2 mRNA and protein. Exposure to both irradiation and ROCKI further enhanced MMP2 expression and had an additive effect on the invasiveness of MIAPaCa-2 cells. Additionally, exposure to MMPI led to significant suppression of both radiation-induced and the basal invasiveness of MIAPaCa-2 cells. This suggests that ROCKI treatment, especially with concomitant X-ray irradiation, can induce invasion of cancer cells and should be used only for certain types of cancer cells. Simultaneous use of inhibitors, ROCKI and MMPI may be effective in suppressing invasiveness under both X-ray-irradiated and non-irradiated conditions.

Genetic variants of NPAT-ATM and AURKA are associated with an early adverse reaction in the gastrointestinal tract of patients with cervical cancer treated with pelvic radiation therapy.

PURPOSE: This study sought to associate polymorphisms in genes related to cell cycle regulation or genome maintenance with radiotherapy (RT)-induced an early adverse reaction (EAR) in patients with cervical cancer. METHODS AND MATERIALS: This study enrolled 243 cervical cancer patients who were treated with pelvic RT. An early gastrointestinal reaction was graded using the National Cancer Institute Common Toxicity Criteria, version 2. Clinical factors of the enrolled patients were analyzed, and 208 patients were grouped for genetic analysis according to their EAR (Grade ≤1, n = 150; Grade ≥2, n = 58). Genomic DNA was genotyped, and association with the risk of EAR for 44 functional single-nucleotide polymorphisms (SNPs) of 19 candidate genes was assessed by single-locus, haplotype, and multilocus analyses. RESULTS: Our analysis revealed two haplotypes to be associated with an increased risk of EAR. The first, comprising rs625120C, rs189037T, rs228589A, and rs183460G, is located between the 5' ends of NPAT and ATM (OR = 1.86; 95% CI, 1.21-2.87), whereas the second is located in the AURKA gene and comprises rs2273535A and rs1047972G (OR = 1.75; 95% CI, 1.10-2.78). A third haplotype, rs2273535T and rs1047972A in AURKA, was associated with a reduced EAR risk (OR = 0.42; 95% CI, 0.20-0.89). The risk of EAR was significantly higher among patients with both risk diplotypes than in those possessing the other diplotypes (OR = 3.24; 95% CI, 1.52-6.92). CONCLUSIONS: Individual radiosensitivity of intestine may be determined by haplotypes in the NPAT-ATM and AURKA genes. These variants should be explored in larger association studies in cervical cancer patients.

Combining carbon ion radiotherapy and local injection of α-galactosylceramide-pulsed dendritic cells inhibits lung metastases in an in vivo murine model.

PURPOSE: Our previous report indicated that carbon ion beam irradiation upregulated membrane-associated immunogenic molecules, underlining the potential clinical application of radioimmunotherapy. The antimetastatic efficacy of local combination therapy of carbon ion radiotherapy and immunotherapy was examined by use of an in vivo murine model. METHODS AND MATERIALS: Tumors of mouse squamous cell carcinoma (NR-S1) cells inoculated in the legs of C3H/HeSlc mice were locally irradiated with a single 6-Gy dose of carbon ions (290 MeV/nucleon, 6-cm spread-out Bragg peak). Thirty-six hours after irradiation, α-galactosylceramide-pulsed dendritic cells (DCs) were injected into the leg tumor. We investigated the effects on distant lung metastases by counting the numbers of lung tumor colonies, making pathologic observations, and assessing immunohistochemistry. RESULTS: The mice with no treatment (control) presented with 168 ± 53.8 metastatic nodules in the lungs, whereas the mice that received the combination therapy of carbon ion irradiation and DCs presented with 2.6 ± 1.9 (P = 0.009) at 2 weeks after irradiation. Immunohistochemistry showed that intracellular adhesion molecule 1, which activates DCs, increased from 6 h to 36 h after irradiation in the local tumors of the carbon ion-irradiated group. The expression of S100A8 in lung tissue, a marker of the lung pre-metastatic phase, was decreased only in the group with a combination of carbon ions and DCs. CONCLUSIONS: The combination of carbon ion radiotherapy with the injection of α-galactosylceramide-pulsed DCs into the primary tumor effectively inhibited distant lung metastases.

Vascular homeostasis regulators, Edn1 and Agpt2, are upregulated as a protective effect of heat-treated zinc yeast in irradiated murine bone marrow.

PURPOSE: To elucidate the mechanism underlying the in vivo radioprotection activity by Zn-containing, heat-treated Saccharomyces cerevisiae yeast (Zn-yeast). MATERIALS AND METHODS: Zn-yeast suspension was administered into C3H/He mice immediately after whole body irradiation (WBI) at 7.5 Gy. Bone marrow was extracted from the mice 6 hours after irradiation and analyzed on a microarray. Expression changes in the candidate responsive genes differentially expressed in treated mice were re-examined by qRT-PCR. The bone marrow was also examined pathologically at 6 h, 3, 7, and 14 days postirradiation. RESULTS: Thirty-six genes, including Edn1 and Agpt2, were identified as candidate responsive genes in irradiated mouse bone marrow treated with Zn-yeast by showing a greater than three-fold change compared with control (no irradiation and no Zn-yeast) mice. The expressions of Cdkn1a, Bax, and Ccng, which are well known as radioresponsive genes, were upregulated in WBI mice and Zn-yeast treated WBI mice. Pathological examination showed the newly formed microvessels lined with endothelial cells, and small round hematopoietic cells around vessels in bone marrow matrix of mice administered with Zn-yeast after WBI, while whole-body irradiated mice developed fatty bone marrow within 2 weeks after irradiation. CONCLUSION: This study identified a possible mechanism for the postirradiation protection conferred by Zn-yeast. The protective effect of Zn-yeast against WBI is related to maintaining the bone marrow microenvironment, including targeting endothelial cells and cytokine release.

Subtypes of cervical adenosquamous carcinomas classified by EpCAM expression related to radiosensitivity.

Adenosquamous carcinoma (ASC) is a relatively uncommon histological subtype of cervical cancer (CC). A point of controversy is the relative prognosis of ASC compared to squamous cell carcinoma (SCC). We hypothesized that ASC could be classified into two intrinsic molecular subtypes with different outcomes. We examined 143 biopsy samples of CC patients to identify a molecule for classification using microarray expression analysis and immunohistochemical analysis (IHA). We found specific expression profiles of candidate genes that distinguished two clusters. All adenocarcinoma (AC) patients were classified into one cluster, and most SCC patients fell into the other cluster. ASC patients were classified across the two clusters, which showed significantly different prognoses. The SCC-like expression signature comprised ANXA8, CK5, IFI16, and nectin-1; and the AC-like signature comprised EpCAM, and TMEM98. These signature-specific genes hypothetically indicated specific pathways by ontological analysis. The AC-like signature suggested an epithelial-mesenchymal transition and activated ß-catenin pathway, while the SCC-like signature suggested keratinocyte differentiation, HPV infection, and p53-mediated apoptosis. IHA revealed that positive expression of the most promising protein, EpCAM, was significantly associated with poor prognosis. In addition, the inhibition of EpCAM expression using siRNA significantly increased radiation-induced cell death in the cervical cell line, ME-180. In conclusion, we identified two possible ASC subtypes associated with different expression profiles and different prognoses. This work provides a novel set of genes that could be used as independent prognostic markers and therapy targets.

Genome wide screen identifies microsatellite markers associated with acute adverse effects following radiotherapy in cancer patients.

BACKGROUND: The response of normal tissues in cancer patients undergoing radiotherapy varies, possibly due to genetic differences underlying variation in radiosensitivity. METHODS: Cancer patients (n = 360) were selected retrospectively from the RadGenomics project. Adverse effects within 3 months of radiotherapy completion were graded using the National Cancer Institute Common Toxicity Criteria; high grade group were grade 3 or more (n = 180), low grade group were grade 1 or less (n = 180). Pooled genomic DNA (gDNA) (n = 90 from each group) was screened using 23,244 microsatellites. Markers with different inter-group frequencies (Fisher exact test P < 0.05) were analyzed using the remaining pooled gDNA. Silencing RNA treatment was performed in cultured normal human skin fibroblasts. RESULTS: Forty-seven markers had positive association values; including one in the SEMA3A promoter region (P = 1.24 x 10(-5)). SEMA3A knockdown enhanced radiation resistance. CONCLUSIONS: This study identified 47 putative radiosensitivity markers, and suggested a role for SEMA3A in radiosensitivity.

Change in fibroblast growth factor 2 expression as an early phase radiotherapy-responsive marker in sequential biopsy samples from patients with cervical cancer during fractionated radiotherapy.

BACKGROUND: The authors previously demonstrated that fibroblast growth factor 2 (FGF2) expression levels in tumor cells (FGF2-T) may be an indicator of the efficacy of radiotherapy in patients with cervical cancer (CC). In the current study, this finding was extended in newly enrolled patients and was investigated further in stromal FGF2 (FGF2-S) expression. METHODS: Sixty-nine patients with CC were recruited as a validation set for the immunohistochemical detection of FGF2-T from biopsy samples that were taken before (pretreatment) or 1 week after the initiation of radiotherapy (midtreatment). The authors also investigated the expression of FGF2 in tumor FGF2-S and investigated vascular endothelial growth factor (VEGF), and cluster of differentiation 31 (CD31) (also called platelet endothelial cell adhesion molecule) in these patients and in an additional 35 patients from a previous study. RESULTS: FGF2 expression was detected in tumor cells from all patients and in stromal cells from 87% of patients. FGF2-T was significantly higher in midtreatment samples (P=.0002), and a high ratio of midtreatment/pretreatment FGF2-T was related significantly to a better prognosis (P=.025). Increased VEGF expression after the initiation of radiotherapy was related significantly to positive FGF2-S in pretreatment samples (P=.035); however, it was not related to prognosis or microvessel density detected by CD31 expression. CONCLUSIONS: Radiation causes a response in tumor cells and adjacent normal cells and changes the extracellular matrix environment. In this study, the authors confirmed their previous findings and demonstrated that changes in FGF2-T expression may be used as a marker to monitor the effectiveness of radiotherapy in patients with CC. These findings should improve patient selection for molecular targeted therapies, such as cytokine inhibitors, after standard-of-care treatment.

Application of carbon-ion beams or gamma-rays on primary tumors does not change the expression profiles of metastatic tumors in an in vivo murine model.

PURPOSE: To clarify how carbon-ion radiotherapy (C-ion) on primary tumors affects the characteristics of subsequently arising metastatic tumor cells. METHODS AND MATERIALS: Mouse squamous cell carcinomas, NR-S1, in synergic C3H/HeMsNrs mice were irradiated with a single dose of 5-50 Gy of C-ion (290 MeV per nucleon, 6-cm spread-out Bragg peak) or gamma-rays ((137)Cs source) as a reference beam. The volume of the primary tumors and the number of metastatic nodules in lung were studied, and histologic analysis and microarray analysis of laser-microdissected tumor cells were also performed. RESULTS: Including 5 Gy of C-ion and 8 Gy of gamma-rays, which did not inhibit the primary tumor growth, all doses used in this study inhibited lung metastasis significantly. Pathologic findings showed no difference among the metastatic tumor nodules in the nonirradiated, C-ion-irradiated, and gamma-ray-irradiated groups. Clustering analysis of expression profiles among metastatic tumors and primary tumors revealed a single cluster consisting of metastatic tumors different from their original primary tumors, indicating that the expression profiles of the metastatic tumor cells were not affected by the local application of C-ion or gamma-ray radiotherapy. CONCLUSION: We found no difference in the incidence and histology, and only small differences in expression profile, of distant metastasis between local C-ion and gamma-ray radiotherapy. The application of local radiotherapy per se or the type of radiotherapy applied did not influence the transcriptional changes caused by metastasis in tumor cells.

Villin1, a novel diagnostic marker for cervical adenocarcinoma.

The number of new cervical adenocarcinoma (AD) cases has risen slowly, however, its histological similarity to other tumor types and the difficulty of identifying the site of the original tumor makes the diagnosis of cervical AD particularly challenging. We investigated a novel molecular biomarker for cervical AD through the integration of multiple methods of genomic analysis. Tumor samples in discovery set were obtained from 87 patients who underwent radiotherapy, including 31 cervical AD. Microarray analysis and quantitative polymerase chain reaction analysis were performed to screen a candidate diagnostic molecule for cervical AD, and its clinical significance was investigated by immunohistochemical analysis (IHC). We found a difference between biopsy samples of AD and squamous cell carcinoma (SCC) in the expression and genomic copy number of Villin1 (VIL1), which maps to 2q35. IHC revealed 14 VIL1-positive tumors; 13 cervical AD and one small cell carcinoma of cervix, while none of SCC or endometrial AD was VIL1-positive. Kaplan-Meier survival curves revealed worse disease-free survival in VIL1-positive tumors. The marker was validated by newly enrolled 65 patients, and VIL1 positive staining showed 52% of sensitivity and 100% of selectivity for cervical AD. In conclusion, we have identified VIL1 as a novel biomarker of cervical AD. VIL1, a major structural component of the brush border cytoskeleton, which was recently found to be an epithelial cell-specific anti-apoptotic protein. Our study suggests the existence of a subtype of cervical tumors which are VIL1 positive with poor radioresponse.

The proangiogenic factor ephrin-A1 is up-regulated in radioresistant murine tumor by irradiation.

While the pre-treatment status of cancer is generally correlated with outcome, little is known about microenvironmental change caused by anti-cancer treatment and how it may affect outcome. For example, treatment may lead to induction of gene expression that promotes resistance to therapy. In the present study, we attempted to find a gene that was both induced by irradiation and associated with radioresistance in tumors. Using single-color oligo-microarrays, we analyzed the gene expression profiles of two murine squamous cell carcinomas, NR-S1, which is highly radioresistant, and SCCVII, which is radiosensitive, after irradiation with 137-Cs gamma rays or carbon ions. Candidate genes were those differentially regulated between NR-S1 and SCCVII after any kind of irradiation. Four genes, Efna1 (Ephrin-A1), Sprr1a (small proline-rich protein 1A), Srgap3 (SLIT-ROBO Rho GTPase activating protein 3) and Xrra1 [RIKEN 2 days neonate thymus thymic cells (NOD) cDNA clone E430023D08 3'], were selected as candidate genes associated with radiotherapy-induced radioresistance. We focused on Efna1, which encodes a ligand for the Eph receptor tyrosine kinase known to be involved in the vascular endothelial growth factor (VEGF) pathway. We used immunohistochemical methods to detect expression of Ephrin-A1, VEGF, and the microvascular marker CD31 in radioresistant NR-S1 tumor cells. Ephrin-A1 was detected in the cytoplasm of NR-S1 tumor cells after irradiation, but not in SCCVII tumor cells. Irradiation of NR-S1 tumor cells also led to significant increases in microvascular density, and up-regulation of VEGF expression. Our results suggest that radiotherapy-induced changes in gene expression related with angiogenesis might also modulate microenvironment and influence responsiveness of tumors.

In-gel multiple displacement amplification of long DNA fragments diluted to the single molecule level.

The isolation and multiple genotyping of long individual DNA fragments are needed to obtain haplotype information for diploid organisms. Limiting dilution of sample DNA followed by multiple displacement amplification is a useful technique but is restricted to short (<5 kb) DNA fragments. In the current study, a novel modification was applied to overcome these problems. A limited amount of cellular DNA was carefully released from intact cells into a mildly heated alkaline agarose solution and mixed thoroughly. The solution was then gently aliquoted and allowed to solidify while maintaining the integrity of the diluted DNA. Exogenously provided Phi29 DNA polymerase was used to perform consistent genomic amplification with random hexameric oligonucleotides within the agarose gels. Simple heat melting of the gel allowed recovery of the amplified materials in a solution of the polymerase chain reaction (PCR)-ready form. The haplotypes of seven SNPs spanning 240 kb of the DNA surrounding the human ATM gene region on chromosome 11 were determined for 10 individuals, demonstrating the feasibility of this new method.

CD44 and Bak expression in IL-6 or TNF-alpha gene knockout mice after whole lung irradiation.

To understand the molecular mechanisms that underlie radiation pneumonitis, we examined whether knockout of the TNF or the IL-6 gene could give mice an inherent resistance to radiation in the acute phase of alveolar damage after thoracic irradiation. The temporal expression of inflammation (CD44) and apoptosis (Bak) markers in lung after thoracic irradiation was measured to determine the degree of alveolar damage. At 4 weeks post-irradiation (10 Gy), small inflammatory foci were observed in all mice, but there were no obvious histological differences between control (C57BL/6JSlc), TNF-alpha knockout (TNF KO), and IL-6 knockout (IL-6 KO) mice. However, immunohistochemical analysis of CD44 and Bak expression over a time course of 2 weeks highlighted significant differences between the three groups. C57BL/6JSlc and TNF KO mice had increased numbers of both CD44-positive and Bak-positive cells after irradiation, while the IL-6 KO mice showed stable levels of CD44 and Bak. In conclusion, the radioresistant status of IL-6 KO mice in the acute phase of alveolar damage after irradiation suggested an important role for IL-6 in radiation pneumonitis.

Gene expression analysis in human malignant melanoma cell lines exposed to carbon beams.

PURPOSE: To elucidate the molecular changes in response to carbon beams (C-ions) in melanoma. MATERIALS AND METHODS: We examined expression profiles of 6 melanoma cell lines exposed to C-ions or X-rays with 2 Gy using single-color microarrays. RESULTS: Twenty-two genes, including nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (NFKBIA), responded to C-ions in all six cell lines, based on analysis of variance (ANOVA) filtering (p < 0.001). We found 173 genes that responded in common to C-ions in four cell lines. We identified many down-regulated genes including the cell cycle - related genes that were more responsive to C-ions than X-rays. In contrast, most of the up-regulated genes including the tumor protein p53 (p53) target genes responded to both C-ions and X-rays. C-ions induced G2/M arrest significantly more than X-rays at 30 h (p < 0.05). CONCLUSION: Our findings suggest that down-regulation of gene expression plays a key role in the response to C-ions. Regulation of cell cycle - related genes and induction of prolonged G2/M arrest may be responsible for the extra sensitivity to C-ions, whereas p53-related genes may have similar roles in the sensitivities to both C-ions and X-rays.

Influence of multiple genetic polymorphisms on genitourinary morbidity after carbon ion radiotherapy for prostate cancer.

PURPOSE: To investigate the genetic risk of late urinary morbidity after carbon ion radiotherapy in prostate cancer patients. METHODS AND MATERIALS: A total of 197 prostate cancer patients who had undergone carbon ion radiotherapy were evaluated for urinary morbidity. The distribution of patients with dysuria was as follows: Grade 0, 165; Grade 1, 28; and Grade 2, 4 patients. The patients were divided (2:1) consecutively into the training and test sets and then categorized into control (Grade 0) and case (Grade 1 or greater) groups. First, 450 single nucleotide polymorphisms (SNPs) in 118 candidate genes were genotyped in the training set. The associations between the SNP genotypes and urinary morbidity were assessed using Fisher's exact test. Then, various combinations of the markers were tested for their ability to maximize the area under the receiver operating characteristics (AUC-ROC) curve analysis results. Finally, the test set was validated for the selected markers. RESULTS: When the SNP markers in the SART1, ID3, EPDR1, PAH, and XRCC6 genes in the training set were subjected to AUC-ROC curve analysis, the AUC-ROC curve reached a maximum of 0.86. The AUC-ROC curve of these markers in the test set was 0.77. The SNPs in these five genes were defined as "risk genotypes." Approximately 90% of patients in the case group (Grade 1 or greater) had three or more risk genotypes. CONCLUSIONS: Our results have shown that patients with late urinary morbidity after carbon ion radiotherapy can be stratified according to the total number of risk genotypes they harbor.

p73 protein expression correlates with radiation-induced apoptosis in the lack of p53 response to radiation therapy for cervical cancer.

PURPOSE: p73 belongs to the p53 tumor suppressor family of genes and can inhibit cell growth in a p53-like manner by inducing apoptosis or cell cycle arrest. Here, we investigated whether p73 could compensate for impaired p53 function in apoptosis induced by radiation therapy (RT) for cervical cancer. METHODS AND MATERIALS: Sixty-eight patients with squamous cell carcinoma of the cervix who received definitive RT combined with (n=37) or without (n=31) cisplatin were investigated. Biopsy specimens were excised from the cervical tumor before RT and after 9 Gy. RESULTS: Mean apoptosis index (AI) was 0.93% before RT and 1.97% after 9 Gy with a significant increase (p<0.001). For all patients, there was a significant correlation between p73 expression positivity after 9 Gy and AI ratio (AI after 9 Gy/AI before RT) (p=0.021). Forty-one patients were regarded as the p53-responding group according to the expression of p53 after 9 Gy, whereas the remaining 27 patients were regarded as the p53-nonresponding group. A significant correlation between p73 expression after 9 Gy and AI ratio was observed in the p53-non-responding group (p<0.001) but not in the p53-responding group (p=0.940). CONCLUSION: Our results suggest that p73 plays an important role in compensating for the lack of p53 function in radiation-induced apoptosis of cervical cancer.