ATM-mediated phosphorylation of the chromatin remodeling enzyme BRG1 modulates DNA double-strand break repair

ATP-dependent chromatin remodeling complexes such as SWI/SNF (SWItch/Sucrose NonFermentable) have been implicated in DNA double-strand break (DSB) repair and damage responses. However, the regulatory mechanisms that control the function of chromatin remodelers in DNA damage response are largely unknown. Here, we show that ataxia telangiectasia mutated (ATM) mediates the phosphorylation of BRG1, the catalytic ATPase of the SWI/SNF complex that contributes to DSB repair by binding γ-H2AX-containing nucleosomes via interaction with acetylated histone H3 and stimulating γ-H2AX formation, at Ser-721 in response to DNA damage. ATM-mediated phosphorylation of BRG1 occurs rapidly and transiently after DNA damage. Phosphorylated BRG1 binds γ-H2AX-containing nucleosomes to form the repair foci. The Ser-721 phosphorylation of BRG1 is critical for binding γ-H2AX-containing nucleosomes and stimulating γ-H2AX formation and DSB repair. BRG1 binds to acetylated H3 peptides much better after phosphorylation at Ser-721 by DNA damage. However, the phosphorylation of Ser-721 does not significantly affect the ATPase and transcriptional activities of BRG1. These results, establishing BRG1 as a novel and functional ATM substrate, suggest that the ATM-mediated phosphorylation of BRG1 facilitates DSB repair by stimulating the association of this remodeler with γ-H2AX nucleosomes via enhancing the affinity to acetylated H3. Our work also suggests that the mechanism of BRG1 stimulation of DNA repair is independent of the remodeler's enzymatic or transcriptional activities.

Phase II study of a polyethoxylated castor oil–free, polymeric micelle formulation of paclitaxel for patients with advanced urothelial cancer previously treated with gemcitabine and platinum

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Background: Paclitaxel-loaded polymeric micelle (Genexol-PM; G-PM) is a novel polyethoxylated castor oil (Cremophor EL [CrEL])-free formulation of paclitaxel. This multicenter phase II study was designed to evaluate the efficacy and safety of the G-PM monotherapy for the treatment of gemcitabine- and cisplatin-refractory advanced urothelial cancer.

Methods: Patients with advanced urothelial cancer received G-PM 240 mg/m2 intravenously over 3 hours every 3 weeks without premedication as salvage chemotherapy after failure to gemcitabine and cisplatin combination chemotherapy. Intrapatient dose escalation of G-PM to 300 mg/m2 was carried out from the second cycle if the prespecified toxicities were not observed after the first cycle.

Results: Thirty-seven patients were enrolled in this study. Platinum-free interval was less than 6 months in 72% of patients and 64% of patients were categorized into intermediate or poor prognostic group. Overall response rate was 19% including one complete response. When response occurs it is long lasting with a median response duration of 7.8 months (range 1.5∼19.3+). The median progression-free survival was 2.7 months (95% CI, 09-4.6) with a median overall survival of 5.7 months (95% CI, 3.1-8.3). The most common major grade 3-4 non-hematologic toxicity was peripheral neuropathy (sensory type 5.6% and motor type 8.3%) followed by infection (5.6%). Grade 3 or worse hematologic toxicities were observed in only one patient.

Conclusions: G-PM showed modest activity with favorable toxicity profiles when used as salvage therapy after gemcitabine-cisplatin failure in advanced urothelial cancer.

No significant financial relationships to disclose.

Source proximity and residential outdoor concentrations of PM(2.5), OC, EC, and PAHs

We examined the effect of proximity to specific mobile, area, and point sources on the residential outdoor concentrations of fine particulate matter PM (PM(2.5)) and several of its particle components. Integrated (48-h) PM(2.5) samples were collected outside non-smoking residences in Elizabeth, NJ, between summer 1999 and spring 2001. Samples were analyzed for PM(2.5) mass, organic and elemental carbon (OC and EC, respectively), trace elements, particle-phase polycyclic aromatic hydrocarbons (p-PAHs), and other important particle species. Information about the proximity of the study homes to potential mobile and area sources of OC, EC, p-PAHs, sulfur (S), and selenium (Se) (including urban interstate highways, local roadways, the Newark International Airport, the Elizabeth seaport, and a nearby refinery in Linden, NJ) were retrieved from a database that included detailed emissions, meteorological, and geographical data for the study area. The dependence of residential outdoor concentrations on source proximity and on various meteorological parameters was then examined for each species by multiple linear regression analysis. As expected, the predicted ambient air concentrations of all particle species (except S, Se) decreased with increasing distance from the sources. Although the enhancement in PM(2.5) and OC levels outside the study homes closest to primary PM sources was modest (e.g., 1.6 and 2.5 times the background levels 37 m from interstate highways), the elevation of EC and p-PAH concentrations was substantial outside the closest study homes (i.e., about 20 times for p-PAHs 37 m from interstate highways and about 14 times for EC 192 m from the refinery in Linden, NJ). The predicted EC concentrations 192 and 500 m from the oil refinery were 22.8 and 3.0 microgC/m(3), compared with an urban background of 1 microgC/m(3). Thus, emissions from this source might dramatically affect EC exposure for residents living in its close proximity.

Adjuvant hormonal therapy for stage I endometrial cancer

Question

What is the role of hormonal therapy as adjuvant therapy in patients with stage i endometrial cancer?

Perspectives

There is little consensus on the role of adjuvant treatment for patients with stage i endometrial cancer. Although the use of hormonal therapy has been established in advanced disease, less agreement has emerged concerning the benefits of adjuvant hormonal therapy for patients with early-stage disease. The objective of the present evidence series was to review the existing literature on the role of hormonal therapy as adjuvant therapy in patients with stage i endometrial cancer.

Outcomes

Reports were sought that included at least one of the following outcomes: overall survival, disease-free survival, recurrence (local, or distant, or both), adverse effects, and quality of life. Because of the potential for long-term adverse effects with adjuvant hormonal treatment in this patient population, especially with regard to thromboembolic or cardiovascular events, the rates of non-cancer-related death were also of interest.

Methodology

The medline, embase, and Cochrane Library databases were systematically searched for randomized controlled trials, practice guidelines, systematic reviews, and meta-analyses. The resulting evidence informed the development of the clinical practice guideline. The systematic review with meta-analyses and practice guideline were approved by the Report Approval Panel of the Program in Evidence-Based Care, and by the Gynecology Cancer Disease Site Group (dsg).

Results

Nine randomized trials and one published meta-analysis comparing adjuvant hormonal therapy with no adjuvant therapy in women with stage i endometrial cancer constituted the evidence base. One trial reported a statistically significant survival benefit with adjuvant progestogen as compared with no further treatment (97% vs. 69%, p < 0.001). In that trial, the treatment group had a higher number of patients with less myometrial invasion, and a lower number of patients with advanced-stage disease. These differences in baseline characteristics between the randomized groups were considered to be clinically important. In addition, the results of that trial were not consistent with those of other trials, and the trial was a source of statistical heterogeneity when data were pooled across trials.

In two of the nine randomized trials, statistically significant recurrence-free benefits were detected with adjuvant hormonal therapy as compared with no further therapy. In one trial, the difference between the rates of recurrence was 16%; however, the methodologic concerns related to that that trial limited its relevance. In the other trial, the difference between the rates of recurrence was 5%. In that trial, patients were at a high risk of recurrence. None of the remaining seven randomized trials reported any significant difference in recurrence rates between treatment groups.

The meta-analysis identified in the literature detected no statistically significant recurrence-free or overall survival benefit associated with adjuvant hormonal therapy as compared with no adjuvant therapy [odds ratio (or): 1.05; 95% confidence interval (ci): 0.88 to 1.24). Those results are consistent with the results of the meta-analysis in the present report, which included an additional two trials (or: 1.10; 95% ci: 0.91 to 1.34).

Practice Guideline

Toll-like receptor expression in patients with renal allograft dysfunction

Toll-like receptor (TLR) is known to be a mediator of innate immunity, but recent reports have shown that TLR provides a link to adaptive immunity involved in allograft rejection. To explore the expression patterns in various conditions of renal transplantation, we examined TLR subunit mRNA expressions in renal allograft biopsies of acute rejection (AR; n = 11), chronic rejection (CR; n = 15), chronic cyclosporine nephrotoxicity (CsAN; n = 22), and immunoglobulin A nephropathy (IgAN; n = 9) patients. Control tissues (n = 7) were obtained from normal renal cortical tissue of renal cell carcinoma patients. The diagnosis was made according to the Banff 97 classification. The expressions of TLR 2, 3, 4, and 9 mRNA were analyzed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) using SYBR green. Statistical analysis was performed using analysis of variance (ANOVA) and the Student t test. TLR 2 and 3 mRNA expressions were not significantly different in any group (P > .05). In contrast, TLR 4 mRNA expression was significantly increased in all allograft groups compared with that of controls, and significantly higher in the CsAN than other transplant groups (P < .05). TLR 9 mRNA expression was up-regulated in CsAN and IgAN compared with AR and CR (P < .05). These results suggested that TLR4 mRNA expression was increased in renal allograft patients with chronic allograft dysfunction. Further studies are needed to correlate TLR subtypes with various causes of graft dysfunction among renal allograft patients.

Patterns of surgical care for uterine cancers in Ontario

OBJECTIVES

To facilitate the planning of future resources for cancer services in Ontario, Cancer Care Ontario commissioned an evaluation of operative services delivered for uterine cancer.

METHODS

Women with an incident diagnosis of a uterine malignancy were identified from 1 April 2003 to 31 March 2004 using the Ontario Cancer Registry. Record linkages were created to other provincial health databases such as the Ontario Health Insurance Plan.

RESULTS

Uterine cancer affected 1,436 women. Disease specific rates of cancer were higher in rural areas and those from the highest income quintiles. Surgery occurred in 94.7% of women. Use of surgery did not appear to vary by SEC, urban/rural residence or LHIN. Gynecologists conducted 76.1% of the operations. Lymphadenectomy took place in 18.7% of women. Lymphadenectomy rates were highest in gynecologic oncologists (43.3%). All women were assessed by CXR. Radiation therapy consults were preformed in half of the women with uterine cancer but treatment was only delivered in half of those seen. Medical oncologists saw about 6.3% of women with uterine cancers.

CONCLUSIONS

There appear to be variations in incidence rates of uterine cancer with disease being more frequent in those of the highest SES. In two-thirds of the population, surgery is delivered in the region where the patient lives. Subspecialty care from gynecologic oncologists was provided to one-third of women. Rates of lymphadenectomy as part of a surgical attempt to assess disease spread appear low. These pilot data would be enhanced with further information such as comorbidity, treatment intent (palliative/curative), histology, grade and stage.

Clinical analysis of multiple primary cancers

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Background: Multiple primary cancers are defined as two or more abnormal growths of tissue occurring simultaneously or abnormal growths of tissues that follow a previous neoplasm but are not metastases of the latter in the same individual. The primary objective of this study was to determine the occurrence, clinical characteristics and prognosis of multiple primary cancers in single institution, respectively. Methods: Between January 1995 and June 2006, patients with multiple primary cancers were selected from a review of patients who had been treated and followed-up in our Ewha Womans University Hospital. Demographic data were obtained from medical records. Results: Two hundred seven patients were selected and patients with multiple primary cancers constituted 1.95% of all malignancies. Male to female ratio was 1.84. (male 134 vs. female 73 patients) The median age first cancer diagnosis was 67 years old in male, 57 in female. The incidence of synchronous cancers is higher than metachronous. (108 vs. 99) and the median time to additional cancers in metachronous group was 35 months. The most frequent cancers was gastrointestinal cancers in both sex synchronously and metachronously. In male, colorectal cancer followed by gastric cancer methchronously (9.1%), genitourinary cancer with another genitourinary cancer synchronously (12.7%) were frequently observed. In female, breast cancer followed by colorectal cancer metachronously (6.8%), gastric cancer with colorectal cancer (6.9%) were frequently observed. The median survival duration was 14.4 months totally from the index diagnosis and synchronous cancers showed lower survival duration than metachronous cancers. (7.4 vs. 26.1 months, p=0.017) Conclusions: Adequate investigations including G-I tract should focus in the first 3 years after initial diagnosis to detect second primary cancers earlier.

No significant financial relationships to disclose.

Risk factors for dietary variety decline among Japanese elderly in a rural community: a 8-year follow-up study from TMIG-LISA

OBJECTIVE

To examine the factors related to the decline of dietary variety among the rural community-dwelling Japanese elderly people and the implication on the planning of elderly people's nutritional improvement program in the future.

DESIGN

A prospective cohort study during 8-year follow-up from 1992 to 2000.

SETTING

This study was conducted in Nangai Village, a rural and mainly agricultural area of Akita Prefecture in the northern part of Honshu, one of four main islands in Japan.

SUBJECTS

A total of 417 elderly people (160 men, 257 women) who completed interviews and food intake frequency surveys conducted in 1992, 1994, 1996, 1998, and 2000 were studied.

METHODS

Dietary variety and variables potentially associated with dietary variety decline were identified from a face-to-face interview at the baseline and 8-year follow-up surveys. The dietary variety was measured using the dietary variety score (DVS), which covers the 10 main food groups in Japanese meals.

RESULTS

During the 8-year follow-up, 36.2% of the subjects showed a decline in dietary variety. Health characteristics also change among the 8-year follow-up and these changes have an effect on the decline of dietary variety. Significant predictors for decline in dietary variety included loss of spouse, deterioration in self-perceived chewing ability, and decrease in intellectual activity score.

CONCLUSIONS

Loss of spouse, deterioration in chewing ability, and decline in intellectual activity may increase the risk of decline in dietary variety in community-dwelling Japanese elderly people.

A phase II study with gemcitabine and split-dose cisplatin in patients with advanced non-small cell lung cancer

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Background: The combination of gemcitabine and cisplatin is among the most active regimens for the treatment of NSCLC. However, the optimal dose and schedule for administration of the two drugs has not yet been determined. We investigated the activity and toxicity of a gemcitabine and split-dose cisplatin regimen in an outpatient setting for patients with advanced non-small cell lung cancer (NSCLC). Methods: From June 2004 to May 2005 patients with stage IIIB or IV who had not had prior chemotherapy entered the study. Treatment consisted of gemcitabine 1,250 mg/m2 and cisplatin 35 mg/m2, both given intravenously on days 1 and 8 every 21 days. Results: Forty-three patients were entered this study. Patient characteristics were as follows: male/female, 32/11; median age (range), 63 (30–76) years; ECOG PS 0/1/2, 7/28/8; stage IIIB/IV, 17/26. A total of 160 cycles were delivered, with a median of 4 cycles (range, 1–6). All patients were evaluable for toxicity. Grade 3 & 4 toxicities according the NCI toxicity criteria included included neutropenia in 7 patients (17%), anemia in 3 (7%), thrombocytopenia in 6 (14%), and emesis in 1 (2%). Of 40 patients assessable for response, one (2.5%) had CR and 22 (55%) had PR. On intent-to-treat basis, the overall response rate was 53% (95% CI, 39–68%). Median time to progression was 6.0 months (range, 1.2–12.0 months) and median overall survival was 13.1 months (range, 1.4–17 months). Conclusions: This regimen with gemcitabine and split-dose cisplatin using a 21-day schedule appears to be active and very well-tolerated in an outpatients setting for patients with advanced NSCLC.

No significant financial relationships to disclose.

A phase II study of irinotecan, oxaliplatin, 5-fluorouracil, leucovorin (FOLFOXIRI) as a first-line chemotherapy in metastatic gastric cancer

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Background: Previous phase II study showed a high efficacy and safety of FOLFOXIRI (irinotecan, oxaliplatin, 5-fluorouracil, leucovorin) combination chemotherapy in metastatic colorectal cancer. This non-randomized open label phase II study evaluated the efficacy and safety of FOLFOXIRI in metastatic or recurrent gastric cancer patients. Methods: Patients with: histologically proven, bidimensionally measurable, metastatic gastric adenocarcinoma, age 18 - 70 years, with a performance status 0 - 2, no prior chemotherapy or at least 12 months after adjuvant therapy, life expectancy > 3 months, signed written informed consent were eligible. Treatment consisted of irinotecan 150 mg/m2 day 1, oxaliplatin 85 mg/m2 day 1, leucovorin 100 mg/m2 day and 5-fluorouracil 2000 mg/m2 as a 48-h continuous infusion starting on day 1, repeated every 2 weeks until unacceptable toxicity, patients’ refusal, or up to 12 cycles. The planned sample size was 48 and the primary endpoint was response rate. Results: From August 2004 to August 2005, 48 patients were prospectively enrolled. The median age was 54 years (24 - 69) and male:female ratio was 1.3:1. In total, 379 cycles were administered with a median of 9 cycles per patient (range, 1–12) and 45/48 patients were evaluable for treatment response. Three patients were not assessable for response due patients’ refusal for further chemotherapy following the first cycle. By per-protocol analysis, the objective response rate was 73.3 % (95% CI, 60.8–85.8) with 2 CRs and 31 PRs. Four patients (9%) had stable disease and 8 patients (18%) had progressive disease. The estimated median survival of all patients was 14.0 months (95% CI, 11.8 - 16.2 ) and the estimated median time-to-progression was 8.9 months (95% CI, 6.7–11.0). In total of 379 cycles administered, most common grade 3/4 toxicities were neutropenia (11% of all cycles) and emesis (12%). Grade 2 peripheral neuropathy occurred in 5 patients. One (2%) patient had severe tumor bleeding and 5 (10%) patients experienced grade 3 diarrhea. Conclusions: FOLFOXIRI combination chemotherapy showed a very promising preliminary anti-tumor activity and was generally well tolerated as a first-line treatment for patients with metastatic gastric cancer.

No significant financial relationships to disclose.