[Efficacy and Prognostic Factors of Estracyt ® in Patients with Castration-Resistant Prostate Cancer (CRPC) : From the Data Analysis of Estracyt ® Special Drug Use Investigation].

Estracyt○R (estramustine phosphate) is a medical drug for prostate cancer with cytotoxic activity causing disruption of microtubule organization and indirect androgen production suppressing activity by its metabolite, estradiol. Based on the data obtained from the Estracyt○R Special Drug Use Investigation which surveyed the clinical efficacy and safety of Estracyt○R in patients with prostate cancer whose relapse of prostate cancer after combined androgen blockade (CAB) therapy was confirmed, we evaluated the progression-free survival, prognostic factor, decrease in prostate specific antigen (PSA) level and safety. This surveillance was conducted at 147 institutions nationwide between October, 2010 and September, 2013 and clinical efficacy was evaluated in 239 cases and safety in 329 cases. The median duration of progression-free survival, PSA progression-free survival and PSA response were 169 days (95%CI, 142-190), 197 days (95%CI, 169-267) and 385 days, respectively. The decrease in PSA level was observed in 125 cases (52.3%). Rate of PSA decline ＞50 and ＞25% were 18.4 and 43.1, respectively, and rate of PSA best response (PSA decline ＞ 50%) was 32.6%. Multivariate analysis demonstrated that long duration of prior CAB therapy, Estracyt○R - pretreatment PSA value and bone metastasis influenced progression-free survival significantly. Adverse events were observed in 127 cases (38.6%). The major adverse events were anorexia which was observed in 35 cases (10.9%), gastrointestinal disorders observed in 32 cases (9.7%), abnormal laboratory test values observed in 31 cases (9.4%) and gynecomastia observed in 16 cases (4.9%). These results suggest the clinical efficacy and safety of Estracyt○R for chemotherapy-naïve castration-resistant prostate cancer (CRPC), and Estracyt○R is regarded as one of the treatment options for patients with CRPC, especially for patients who had long duration of prior CAB therapy.

UVB sensitivity and cyclobutane pyrimidine dimer (CPD) photolyase genotypes in cultivated and wild rice species.

We investigated the UVB-sensitivity in 12 rice strains belonging to two cultivated species (O. sativa and O. glaberrima) and three wild species (O. barthii, O. meridionalis and O. rufipogon) of rice possessing the AA genome, while focusing on the CPD photolyase activity and the genotypes of CPD photolyase. Although the UVB sensitivity, CPD photolyase activity, and CPD photolyase genotype varied widely among these rice species, the sensitivity to UVB radiation depended on the activity of the CPD photolyase, regardless of grass shape, habitat, or species. The rice strains examined here clearly divided into three groups based on the CPD photolyase activity, and the activity of the strains greatly depended on amino acid residues at positions 126 and 296, with the exception of the W1299 strain (O. meridionalis). The amino acid residues 126 and 296 of CPD photolyase in Sasanishiki strain (O. sativa), which showed higher enzymatic activity and more resistance to UVB, were glutamine (Gln) and Gln, respectively. An amino acid change at position 126 from Gln to arginine ("Nori"-type) in the photolyase led to a reduction of enzymatic activity. Additionally, an amino acid change at position 296 from Gln to histidine led to a further reduction in activity. The activity of the W1299 strain, which possesses a "Nori"-type CPD photolyase, was the highest among the strains examined here, and was similar to that of the Sasanishiki. The CPD photolyase of the W1299 contains ten amino acid substitutions, compared to Sasanishiki. The alterations in amino acid residues in the W1299 CPD photolyase compensated for the reduction in activity caused by the amino acid substitutions at positions 126. Knowledge of the activity of different CPD photolyase genotypes will be useful in developing improved rice cultivars.

Biochemical and biological properties of DNA photolyases derived from utraviolet-sensitive rice cultivars.

Class I and class II CPD photolyases are enzymes which repair pyrimidine dimers using visible light. A detailed characterization of class I CPD photolyases has been carried out, but little is known about the class II enzymes. Photolyases from rice are suitable for functional analyses because systematic breeding for long periods in Asian countries has led to the selection of naturally occurring mutations in the CPD photolyase gene. We report the biochemical characterization of rice mutant CPD photolyases purified as GST-form from Escherichia coli. We identified three amino acid changes, Gln126Arg, Gly255Ser, and Gln296His, among which Gln but not His at 296 is important for complementing phr-defective E. coli, binding UV-damage in E. coli, and binding thymine dimers in vitro. The photolyase with Gln at 296 has an apoenzyme:FAD ratio of 1 : 0.5 and that with His at 296 has an apoenzyme:FAD ratio of 1 : 0.12-0.25, showing a role for Gln at 296 in the binding of FAD not in the binding of thymine dimer. Concerning Gln or Arg at 126, the biochemical activity of the photolyases purified from E. coli and complementing activity for phr-defective E. coli are similarly proficient. However, the sensitivity to UV of cultivars differs depending on whether Gln or Arg is at 126. The role of Gln and Arg at 126 for photoreactivation in rice is discussed.

Increase in CPD photolyase activity functions effectively to prevent growth inhibition caused by UVB radiation.

Rice cultivars vary widely in their sensitivity to ultraviolet B (UVB) and this has been correlated with cyclobutane pyrimidine dimer (CPD) photolyase mutations that alter the structure/function of this photorepair enzyme. Here, we tested whether CPD photolyase function determines the UVB sensitivity of rice (Oryza sativa) by generating transgenic rice plants bearing the CPD photolyase gene of the UV-resistant rice cultivar Sasanishiki in the sense orientation (S-B and S-C lines) or the antisense orientation (AS-D line). The S-B and S-C plants had 5.1- and 45.7-fold higher CPD photolyase activities than the wild-type, respectively, were significantly more resistant to UVB-induced growth damage, and maintained significantly lower CPD levels in their leaves during growth under elevated UVB radiation. Conversely, the AS-D plant had little photolyase activity, was severely damaged by elevated UVB radiation, and maintained higher CPD levels in its leaves during growth under UVB radiation. Notably, the S-C plant was not more resistant to UVB-induced growth inhibition than the S-B plant, even though it had much higher CPD photolyase activity. These results strongly indicate that UVB-induced CPDs are one of principal causes of UVB-induced growth inhibition in rice plants grown under supplementary UVB radiation, and that increasing CPD photolyase activity can significantly alleviate UVB-caused growth inhibition in rice. However, further protection from UVB-induced damage may require the genetic enhancement of other systems as well.

Sensitivity of rice to ultraviolet-B radiation.

BACKGROUND: Depletion of the stratospheric ozone layer leads to an increase in ultraviolet-B (UVB: 280-320 nm) radiation reaching the earth's surface, and the enhanced solar UVB radiation predicted by atmospheric models will result in reduction of growth and yield of crops in the future. Over the last two decades, extensive studies of the physiological, biochemical and morphological effects of UVB in plants, as well as the mechanisms of UVB resistance, have been carried out. SCOPE: In this review, we describe recent research into the mechanisms of UVB resistance in higher plants, with an emphasis on rice (Oryza sativa), one of the world's most important staple food crops. Recent studies have brought to light the following remarkable findings. UV-absorbing compounds accumulating in the epidermal cell layers have traditionally been considered to function as UV filters, and to play an important role in countering the damaging effects of UVB radiation. Although these compounds are effective in reducing cyclobutane pyrimidine dimer (CPD) induction in plants exposed to a challenge exposure to UVB, certain levels of CPD are maintained constitutively in light conditions containing UVB, regardless of the quantity or presence of visible light. These findings imply that the systems for repairing DNA damage and scavenging reactive oxygen species (ROS) are essential for plants to grow in light conditions containing UVB. CONCLUSION: CPD photolyase activity is a crucial factor determining the differences in UVB sensitivity between rice cultivars. The substitution of one or two bases in the CPD photolyase gene can alter the activity of the enzyme, and the associated resistance of the plant to UVB radiation. These findings open up the possibility, in the near future, of increasing the resistance of rice to UVB radiation, by selective breeding or bioengineering of the genes encoding CPD photolyase.

Changes in grain size and grain storage protein of rice (Oryza Sativa L.) in response to elevated UV-B radiation under outdoor conditions.

Variation in growth, grain size and grain storage protein content of rice (Oryza sativa L.) in response to elevated UV-B radiation under sunlight was examined in a cool rice-growing region of Miyagi Prefecture, Japan, in 1999, 2001 and 2002. Tiller number, dry mass, panicle number, grain yield and grain size significantly decreased under elevated UV-B radiation in 2001 and 2002. The effects of elevated UV-B radiation on the reduction of each growth parameter were greatly enhanced by daily lower temperature during the ripening stage in those two years. On the contrary, total grain nitrogen content and grain storage protein content significantly increased under elevated UV-B radiation in 2001 and 2002. Among grain storage proteins, glutelin content significantly increased but albumin-globulin and prolamin contents did not. It was thus evident that not only grain size but also grain storage protein of rice was markedly influenced due to elevated UV-B radiation.

Spontaneously occurring mutations in the cyclobutane pyrimidine dimer photolyase gene cause different sensitivities to ultraviolet-B in rice.

Sensitivity to ultraviolet-B (UVB) radiation (280-320 nm) varies widely among rice cultivars. We previously indicated that UV-resistant rice cultivars are better able to repair cyclobutane pyrimidine dimers (CPDs) through photorepair than are UV-sensitive cultivars. In this paper, we report that UVB sensitivity in rice, in part, is the result of defective CPD photolyase alleles. Surjamkhi (indica) exhibited greater sensitivity to UVB radiation and was more deficient in CPD photorepair ability compared with UV-resistant Sasanishiki (japonica). The deficiency in CPD photorepair in Surjamkhi resulted from changes in two nucleotides at positions 377 and 888 in the photolyase gene, causing alterations of two deduced amino acids at positions 126 and 296 in the photolyase enzyme. A linkage analysis in populations derived from Surjamkhi and Sasanishiki showed that UVB sensitivity is a quantitative inherited trait and that the CPD photolyase locus is tightly linked with a quantitative trait locus that explains a major portion of the genetic variation for this trait. These results suggest that spontaneously occurring mutations in the CPD photolyase gene cause different degrees of sensitivity to UVB in rice, and that the resistance of rice to UVB radiation could be increased by increasing the photolyase function through conventional breeding or bioengineering.

qUVR-10, a major quantitative trait locus for ultraviolet-B resistance in rice, encodes cyclobutane pyrimidine dimer photolyase.

Rice qUVR-10, a quantitative trait locus (QTL) for ultraviolet-B (UVB) resistance on chromosome 10, was cloned by map-based strategy. It was detected in backcross inbred lines (BILs) derived from a cross between the japonica variety Nipponbare (UV resistant) and the indica variety Kasalath (UV sensitive). Plants homozygous for the Nipponbare allele at the qUVR-10 locus were more resistant to UVB compared with the Kasalath allele. High-resolution mapping using 1850 F(2) plants enabled us to delimit qUVR-10 to a <27-kb genomic region. We identified a gene encoding the cyclobutane pyrimidine dimer (CPD) photolyase in this region. Activity of CPD photorepair in Nipponbare was higher than that of Kasalath and nearly isogenic with qUVR-10 [NIL(qUVR-10)], suggesting that the CPD photolyase of Kasalath was defective. We introduced a genomic fragment containing the CPD photolyase gene of Nipponbare to NIL(qUVR-10). Transgenic plants showed the same level of resistance as Nipponbare did, indicating that the qUVR-10 encoded the CPD photolyase. Comparison of the qUVR-10 sequence in the Nipponbare and Kasalath alleles revealed one probable candidate for the functional nucleotide polymorphism. It was indicated that single-base substitution in the CPD photolyase gene caused the alteration of activity of CPD photorepair and UVB resistance. Furthermore, we were able to develop a UV-hyperresistant plant by overexpression of the photolyase gene.

Ultraviolet-B sensitivities in Japanese lowland rice cultivars: cyclobutane pyrimidine dimer photolyase activity and gene mutation.

There is a cultivar difference in the response to ultraviolet-B (UVB: 280-320 nm) in rice (Oryza sativa L.). Among Japanese lowland rice cultivars, Sasanishiki, a leading Japanese rice cultivar, is resistant to the damaging effects of UVB while Norin 1, a close relative, is less resistant. We found previously that Norin 1 was deficient in cyclobutane pyrimidine dimer (CPD) photorepair ability and suggested that the UVB sensitivity in rice depends largely on CPD photorepair ability. In order to verify that suggestion, we examined the correlation between UVB sensitivity and CPD photolyase activity in 17 rice cultivars of progenitors and relatives in breeding of UV-resistant Sasanishiki and UV-sensitive Norin 1. The amino acid at position 126 of the deduced amino acid sequence of CPD photolyase in cultivars including such as Norin 1 was found to be arginine, the CPD photolyase activities of which were lower. The amino acid at that position in cultivars including such as Sasanishiki was glutamine. Furthermore, cultivars more resistant to UVB were found to exhibit higher photolyase activities than less resistant cultivars. These results emphasize that single amino acid alteration from glutamine to arginine leads to a deficit of CPD photolyase activity and that CPD photolyase activity is one of the main factors determining UVB sensitivity in rice.

EFFECT OF POLYOXIN ON THE MORPHOGENESIS OF THE FUNGUS, ALTERNARIA TOMATO WITH SPECIAL REFERRENCE TO PHOTOSPORULATION.

Photosporulation of Alternaria tomato was very little influenced by polyoxin at concentrations below 10 µg/ml, although hyphae and conidia were morphologically affected. The hyphae grown in the presence of polyoxin were easily disrupted.