National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol B-18 was initiated in 1988 to determine whether four cycles of doxorubicin/cyclophosphamide given preoperatively improve survival and disease-free survival (DFS) when compared with the same chemotherapy given postoperatively. Secondary aims included the evaluation of preoperative chemotherapy in downstaging the primary breast tumor and involved axillary lymph nodes, the comparison of lumpectomy rates and rates of ipsilateral breast tumor recurrence (IBTR) in the two treatment groups, and the assessment of the correlation between primary tumor response and outcome. Initially published findings were based on a follow-up of 5 years; this report updates results through 9 years of follow-up. There continue to be no statistically significant overall differences in survival or DFS between the two treatment groups. Survival at 9 years is 70% in the postoperative group and 69% in the preoperative group (P = .80). DFS is 53% in postoperative patients and 55% in preoperative patients (P = .50). A statistically significant correlation persists between primary tumor response and outcome, and this correlation has become statistically stronger with longer follow-up. Patients assigned to preoperative chemotherapy received notably more lumpectomies than postoperative patients, especially among patients with tumors greater than 5 cm at study entry. Although the rate of IBTR was slightly higher in the preoperative group (10.7% versus 7.6%), this difference was not statistically significant. Marginally statistically significant treatment-byage interactions appear to be emerging for survival and DFS, suggesting that younger patients may benefit from preoperative therapy, whereas the reverse may be true for older patients. [
Our study showed that doses of intravenous polymyxin B are best scaled by total body weight. Importantly, dosage selection of this drug should not be based on renal function.
We found a plasma microRNA panel that has considerable clinical value in diagnosing early-stage HCC. Thus, patients who would have otherwise missed the curative treatment window can benefit from optimal therapy.
Colistin was substantially less effective in lung infection. The pharmacokinetic/pharmacodynamic target values will assist in the design of optimized dosage regimens.
SUMMARY
Nucleosome organization influences gene activity by controlling DNA accessibility to transcription machinery. Here, we develop a chemical biology approach to determine mammalian nucleosome positions genome-wide. We uncovered surprising features of nucleosome organization in mouse embryonic stem cells. In contrast to the prevailing model, we observe that for nearly all mouse genes a class of fragile nucleosomes occupies previously designated nucleosome-depleted regions around transcription start sites and transcription termination sites. We show that nucleosomes occupy DNA targets for a subset of DNA-binding proteins, including CTCF and pluripotency factors. Furthermore, we provide evidence that promoter-proximal nucleosomes, with the +1 nucleosome in particular, contribute to the pausing of RNA polymerase II. Lastly, we find a characteristic preference for nucleosomes at exon-intron junctions. Taken together, we establish an accurate method for defining the nucleosome landscape, and provide a valuable resource for studying nucleosome-mediated gene regulation in mammalian cells.
SUMMARY
Many mutant p53 proteins (mutp53s) exert oncogenic gain-of-function (GOF) properties, but the mechanisms mediating these functions remain poorly defined. We show here that GOF mutp53s inhibit AMP-activated protein kinase (AMPK) signaling in head and neck cancer cells. Conversely, downregulation of GOF mutp53s enhances AMPK activation under energy stress, decreasing the activity of the anabolic factors acetyl-CoA carboxylase and ribosomal protein S6 and inhibiting aerobic glycolytic potential and invasive cell growth. Under conditions of energy stress, GOF mutp53s, but not wild-type p53, preferentially bind to the AMPKα subunit and inhibit AMPK activation. Given the importance of AMPK as an energy sensor and tumor suppressor that inhibits anabolic metabolism, our findings reveal that direct inhibition of AMPK activation is an important mechanism through which mutp53s can gain oncogenic function.
Patients with stage IIIB and IIIC colon cancer represent a heterogeneous group of patients with the majority either overstaged or understaged. LNR is a more accurate prognostic method for stage III colon cancer patients. We propose an algorithm to incorporate LNR into current AJCC staging system.
The therapeutic benefit of tamoxifen in patients with hormone-dependent breast cancer is limited by acquired resistance to this drug. To investigate the biological alterations responsible for tamoxifen resistance, an in vitro model was established. After 6-month continuous exposure to tamoxifen (10
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