Green cocoon-derived sericin reduces cellular damage caused by radiation in human keratinocytes

Radiation therapy used in the treatment of cancer causes skin damage, and no method of care has been established thus far. Recently, it has become clear that sericin derived from silkworm cocoons has moisturizing and antioxidant functions. In addition, green cocoon-derived sericin, which is rich in flavonoids, may have enhanced functions. However, whether this green cocoon-derived sericin can reduce radiotherapy-induced skin damage is unclear. In the present study, we aimed at establishing care methods to reduce skin cell damage caused by X-irradiation using green cocoon-derived sericin. We investigated its effect on human keratinocytes using lactate dehydrogenase activity to indicate damage reduction. Our results showed that green cocoon-derived sericin reduced cell damage caused by X-irradiation. However, this effect was not observed when cells were treated before X-irradiation or with a sericin derived from white cocoons. In addition, green cocoon-derived sericin decreased the levels of reactive oxygen species and lipid peroxidation. Our results suggest that green cocoon sericin mitigates the damaging effect of X-irradiation on cells, hence presenting potential usefulness in reducing skin damage from radiation therapy and opening new avenues in the care of cancer patients.

Loss of the cystine/glutamate antiporter in melanoma abrogates tumor metastasis and markedly increases survival rates of mice

The cystine/glutamate antiporter, system x_c ^- , is essential for the efficient uptake of cystine into cells. Interest in the mechanisms of system x_c ^- function soared with the recognition that system x_c ^- presents the most upstream node of ferroptosis, a recently described form of regulated necrosis relevant for degenerative diseases and cancer. Since targeting system x_c ^- hold the great potential to efficiently combat tumor growth and metastasis of certain tumors, we disrupted the substrate-specific subunit of system x_c ^- , xCT (SLC7A11) in the highly metastatic mouse B16F10 melanoma cell line and assessed the impact on tumor growth and metastasis. Subcutaneous injection of tumor cells into the syngeneic B16F10 mouse melanoma model uncovered a marked decrease in the tumor-forming ability and growth of KO cells compared to control cell lines. Strikingly, the metastatic potential of KO cells was markedly reduced as shown in several in vivo models of experimental and spontaneous metastasis. Accordingly, survival rates of KO tumor-bearing mice were significantly prolonged in contrast to those transplanted with control cells. Analyzing the in vitro ability of KO and control B16F10 cells in terms of endothelial cell adhesion and spheroid formation revealed that xCT expression indeed plays an important role during metastasis. Hence, system x_c ^- emerges to be essential for tumor metastasis in mice, thus qualifying as a highly attractive anticancer drug target, particularly in light of its dispensable role for normal life in mice.

Quality of Life and Symptom Burden among Chronic Kidney Disease of Uncertain Etiology (CKDu) Patients in Girandurukotte, Sri Lanka

Symptom burden and health-related quality of life (HRQOL) are important predictors of how a disease affects patients' lives, especially for endemic health problems such as chronic kidney disease of uncertain etiology (CKDu). Our study describes symptom burden, HRQOL, and associated demographic and clinical variables in CKDu patients in the Girandurukotte area, Sri Lanka. A cross-sectional study included 120 CKDu patients attending the renal clinic in the endemic area. The instruments applied were the Kidney Disease Quality of Life-Short Form (KDQOL-SFTM) version 1.3 and CKD Symptom Index-Sri Lanka. Socio-demographic, disease-related, and anthropometric variables were also investigated. The mean age of patients was 61.87 (SD 11.31), while 69.2% were male. The mean glomerular filtration rate was 28.17 (SD 14.03) mL/min/1.73 min2, and 70.8% were anemic. Bone/joint pain was the most experienced symptom while the median number of symptoms reported by patients was 5 (IQR 3-7). The mean symptom burden, physical component summary, mental component summary, and kidney-disease-specific component scores were 12.71 (SD 10.45), 68.63 (SD 19.58), 78.53 (SD 18.78), and 81.57 (SD 5.86), respectively. Age was found to be a significant predictor of HRQOL, while hemoglobin level and being a farmer were significant predictors of symptom burden. Our data indicate that CKDu patients in all stages experience at least one symptom affecting all aspects of HRQOL.

Interaction between Esophageal Squamous Cell Carcinoma and Adipose Tissue in Vitro

Esophageal squamous cell carcinoma (ESCC) develops within the squamous epithelial layer and invades the submucosa to the subadventitia that has adipose tissue (AT). AT seems critical to ESCC progression, but the underlying mechanism is unknown. We aimed to address the association between ESCC and AT in vitro. ESCC cells were cultured on rat or human subcutaneous AT-embedded or -non-embedded collagen gel. AT promoted the growth of ESCC cells and inhibited their apoptosis. AT promoted the expression of the squamous differentiation marker involucrin in ESCC cells. AT accelerated the expression of invasion-related factors in poorly differentiated ESCC cells only. AT promoted the expression of phosphorylated-insulin-like growth factor-1 receptor in ESCC cells, whereas it inhibited that of the human epidermal growth factor receptor 2. Insulin-like growth factor-1, but not leptin, adiponectin, or resistin, promoted and inhibited the growth and apoptosis of ESCC cells, respectively. In turn, ESCC cells decreased the production of these adipokines in AT and the number of preadipocytes and mesenchymal stem cell-like cells, which developed from AT. These results suggest that i) AT may influence the progression of ESCC with increased growth or invasion and decreased apoptosis through insulin-like growth factor-1/insulin-like growth factor-1 receptor signaling, ii) AT may affect human epidermal growth factor receptor 2-targeted therapy; and iii) the cancer cells may affect adipokine production in AT.

Phase II study of a combination of S-1 and weekly paclitaxel in patient with advanced or recurrent gastric cancer

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Background: Based on the results of our phase I study on a combination of S-1 (tegafur, oxonic acid, and CDHP) and weekly paclitaxel (PTX) for advanced or recurrent gastric cancer (ARGC) (Ueda et al, ASCO 2004), we conducted a multi-center phase II study to prospectively evaluate efficacy, QOL, and toxicity of S-1 plus weekly PTX in patients with ARGC. Methods: Eligibility included patients with histologically-proven ARGC, 20–80 years old, having a ECOG performance status (PS) of 0–2 and adequate organ functions, and having received no prior chemotherapy except postoperative adjuvant therapies without taxanes. S-1 was given orally at a dose of 80 mg/m2/day for 14 consecutive days (days 1–14) followed by a 2-week rest. PTX was administered weekly as a 1-hour intravenous infusion on days 1, 8, and 15. This treatment was repeated every 4-weeks as one cycle. Results: Fifty-four patients with measurable lesions (RECIST) were enrolled between Feb. 2004 and Nov. 2005. Histologically, a half of the patients had differentiated type and the other patients had undifferentiated type adenocarcinoma. The median age was 61 (range, 38–78). Three-fourths were male patients. The PS was 0/1/2 in 47/6/1 patients respectively. Thirty nine were primary cases and 15 were recurrent cases after gastrectomy. Treatment was terminated in two patients for toxicities and in one patient for refusal during the first cycle; thus compliance of 94.4%. A total of 254 cycles were administered (median 4.7, range 2–14), and 45 patients were assessable efficacy and toxicity until Dec. 2005. In these 45 assessable patients, 2 CRs and 27 PRs were obtained, resulting in an overall response rate of 64.4%. Twelve pts (26.7%) had stable disease, and 4 pts (8.9%) progressed. The tumor control rate was 91.1%. Conclusions: The combination of S-1 and weekly PTX is highly active for ARGC, and can be given safely with good tolerance and convenience profile. It is a candidate for the standard regimen and expected to contribute to better prognosis and QOL in ARGC patients.

No significant financial relationships to disclose.

[Activities of thymidylate synthase and dihydropyrimidine dehydrogenase in patients with colorectal cancer]

Between 1998 and 2001, 82 colorectal cancers were resected in our hospital. The activities of TS and DPD were evaluated. TS activities in tumor tissues were significantly higher than in normal tissue, but the DPD activities had no significant difference between them. TS and DPD showed a correlation between normal and tumor tissues in stage III or IV patients. The TS value of patients with recurrence tended to be higher than that of patients with no recurrence. Especially in stage I or II patients with recurrence, who were administered 5-FU before recurrence, the TS value was significantly higher than in non-treated patients. In stage III or IV patients, it was considered that DPD prevention was important for 5-FU to effectively prevent TS. The TS value might be a new prospective risk factor for recurrence. Moreover, TS and DPD would be the index of biological malignancy.

Hypoxic conditions restore lost sensitivity to the growth inhibitory effect of transforming growth factor beta-1 (TGF beta-1) in proliferating rat hepatocytes in vitro

TGF beta-1 is known to be a growth inhibitor of regenerating liver, and an inducer of hepatocyte apoptosis in primary culture. However, hepatocytes can proliferate after partial hepatectomy even at high serum TGF beta-1 concentrations. In this study we used the primary cultures of rat hepatocytes for 10 days to investigate how TGF beta-1 affects proliferating hepatocytes. DNA synthesis peaked on day 8 of culture, and TGF beta-1-induced apoptosis was significantly suppressed on day 8 compared to days 2, 5, and 10. Flow-cytometric analysis revealed that hepatocytes that had incorporated BrdU were resistant to the apoptotic effect of TGF beta-1, and Northern blot analysis showed that TGF beta receptor mRNA was down-regulated on day 8. Hypoxic conditions restores TGF beta receptor mRNA expression and the lost sensitivity of proliferating hepatocyte to TGF beta-1.

[Long-term complete response in two cases of liver metastases from rectal and gastric cancer treated with intra-arterial infusion chemotherapy of leucovorin and 5-fluorouracil]

Intra-arterial infusion chemotherapy combined with leucovorin (LV) and 5-fluorouracil (5-FU) was performed in two patients with multiple metastases from rectal and gastric cancer. In each patient LV 45 mg was infused as a bolus just before and after 5-FU 1,000 mg/4 hrs administration. Thereafter 5-FU dose was decreased gradually. This regimen was principally repeated weekly on an outpatient basis. In both patients PR was detectable 3 and 4 months after the beginning of chemotherapy, and CR was obtained in 21 and 6 months, respectively. Neither patient showed any signs of recurrence and are in good health 35 and 30 months after initiation of chemotherapy. These findings suggest that our protocol has an excellent anti-tumor effect and improves the QOL in some patients for a long time.

Recovery of the contact site A glycoprotein of Dictyostelium discoideum from sodium dodecyl sulfate-polyacrylamide gel and characteristics of monoclonal antibodies against the recovered protein

Monoclonal antibodies were produced against a cell-cell adhesion (contact site A) glycoprotein of Dictyostelium discoideum, isolated by preparative gel electrophoresis. The glycoprotein was recovered by electroelution from a polyacrylamide gel strip and used for the production of monoclonal antibodies. Four of the five antibodies obtained bound specifically to the protein moiety of the contact site A glycoprotein. The specificities of the antibodies were in striking contrast to those of antibodies raised against the contact site A glycoprotein purified by Triton X-114 phase separation and DEAE chromatography. The majority of the latter antibodies recognized the carbohydrate moiety of the contact site A glycoprotein and cross-reacted heavily with other membrane glycoproteins.