Objectively measured physical activity during chemotherapy in colon cancer patients.

PURPOSE: Although adjuvant chemotherapy can have an impact on physical activity (PA), PA level has not been studied in patients with stage II-III colon cancer. This study investigated PA levels during and between chemotherapy cycles. METHODS: We objectively measured PA levels for 2 weeks during the 2nd and 11th chemotherapy cycles. In addition, self-reported PA levels were assessed before chemotherapy initiation, during 2nd, 6th, and 12th chemotherapy cycles. This study included 22 men and 33 women with stage II-III colon cancer patients (57 ± 9 years). RESULTS: Before the initiation of chemotherapy, most cancer patients were minimally active. Compared with the 1st week of chemotherapy, moderate- and light-intensity PA levels significantly increased during the 2nd week of chemotherapy. Patients increased moderate- and light-intensity PA from 217.4 to 290.3 min per week and from 585.7 to 657.8 min per week, respectively (p < 0.01). PA levels did not show any difference between the 2nd and 12th cycles when objectively measured, or between baseline and 2nd, 6th, and 12th cycles when self-reported. CONCLUSION: PA levels during chemotherapy cycles are initially low, and then increase towards the end of the cycle; however, PA levels do not change between chemotherapy cycles. Future work with broader and larger samples size is recommended.

Loss of Arabidopsis Halotolerance 2-like (AHL), a 3'-phosphoadenosine-5'-phosphate phosphatase, suppresses insensitive response of Arabidopsis thaliana ring zinc finger 1 (atrzf1) mutant to abiotic stress.

KEY MESSAGE: Destruction of PAP phosphatase AHL suppresses atrzf1 phenotype in abiotic stress responses. AHL plays an intermediate role in the regulation of proline accumulation by PAP nucleotidase. Proline (Pro) metabolism is important for environmental responses, plant development, and growth. However, the role of Pro in abiotic stress process is unclear. Using atrzf1 (Arabidopsis thaliana ring zinc finger 1) mutant as a parental line for T-DNA tagging mutagenesis, we identified a suppressor mutant designated as proline content alterative 17 (pca17) that suppressed insensitivity of atrzf1 to abiotic stresses during early seedling growth. Pro content of pca17 was lower than that in both wild type (WT) and atrzf1 while complementary lines were less sensitive to abscisic acid (ABA) and abiotic stresses compared to WT. Thermal Asymmetric Interlaced (TAIL)-PCR of pca17 showed that T-DNA was inserted at site of At5g54390 (AHL for Arabidopsis Halotolerance 2-like) encoding 3'-phosphoadenosine-5'-phosphate (PAP) phosphatase. Under drought stress condition, products of sulfate metabolism such as PAP and adenosine monophosphate were significantly lower in pca17 than those in WT and atrzf1. Furthermore, pca17 showed significantly higher levels of several important drought parameters including malondialdehyde, ion leakage, and water loss than WT and atrzf1. Fluorescence signal of green fluorescent protein (GFP)-tagged AHL was quite strong in nuclei of the root and guard cells of transgenic seedlings. Additionally, AHL promoter-ß-glucuronidase (GUS) construct revealed substantial gene expression in vasculature tissues and pollen. Collectively, these findings demonstrate that pca17 acts as a dominant suppressor mutant of atrzf1 in abiotic stress response by modulating proline and sulfate metabolism.