Citations

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited human renal disease and is caused by mutations in two genes, PKD1 (85%) and PKD2 (15%). Cyst epithelial cells are characterised by a complex cellular phenotype including changes in proliferation, apoptosis, basement membrane composition and apicobasal polarity. Since polycystin 1 (PC1), the PKD1 protein, has been located in the basolateral membrane of kidney epithelial cells, we hypothesised that it might have a key role in mediating or stabilising cell-cell interactions. In non-ciliated L929 cells, stable or transient surface expression of the PC1 extracellular domain was sufficient to confer an adhesive phenotype and stimulate junction formation. In MDCK cells, we found that PC1 was recruited to the lateral membranes coincident with E-cadherin within 30 minutes after a `calcium switch'. Recruitment of both proteins was significantly delayed when cells were treated with a PC1 blocking antibody raised to the PKD domains. Finally, PC1 and E-cadherin could be coimmunoprecipitated together from MDCK cells. We conclude that PC1 has a key role in initiating junction formation via initial homophilic interactions and facilitates junction assembly and the establishment of apicobasal polarity by E-cadherin recruitment.

Abstract Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of myeloid cells that inhibit T-cell activity and contribute to the immune suppression characteristic of most tumors. We discovered that bone marrow (BM) progenitor cells from the Muc1 knockout (KO) mice differentiated into CD11b+Gr1+ MDSCs in vitro under granulocyte macrophage colony-stimulating factor and interleukin-4 signaling. MUC1 is a tumor-associated mucin and its cytoplasmic tail (MUC1-CT) can regulate β-catenin to promote oncogenesis. Given the importance of β-catenin in hematopoiesis, we hypothesized that the MUC1 regulation of β-catenin is important for MDSC development. Our current study shows that the aberrant development of BM progenitors into CD11b+Gr1+ MDSCs is dependent on the down-regulation of β-catenin levels that occurs in the absence of Muc1. In light of this, KO mice showed enhanced EL4 tumor growth and were able to better tolerate allogeneic BM185 tumor growth, with an accumulation of CD11b+Gr1+ cells in the blood and tumor-draining lymph nodes. WT mice were able to similarly tolerate allogeneic tumor growth when they were injected with CD11b+Gr1+ cells from tumor-bearing KO mice, suggesting that tolerance of allogeneic tumors is dependent on MDSC-mediated immune suppression. This further delineates the ability of Muc1 to control MDSC development, which could directly affect tumorigenesis. Knowledge of the biology by which Muc1 regulates the development of myeloid progenitors into MDSCs would also be very useful in enhancing the efficacy of cancer vaccines in the face of tumor immune suppression. [Cancer Res 2009;69(8):3554–62]

Abstract Waldenström's macroglobulinemia (WM) is a distinct clinicobiological entity defined as a B-cell neoplasm characterized by a lymphoplasmacytic infiltrate in bone marrow (BM) and IgM paraprotein production. Cytogenetic analyses were historically limited by difficulty in obtaining tumor metaphases, and the genetic basis of the disease remains poorly defined. Here, we performed a comprehensive analysis in 42 WM patients by using a high-resolution, array-based comparative genomic hybridization approach to unravel the genetic mechanisms associated with WM pathogenesis. Overall, 83% of cases have chromosomal abnormalities, with a median of three abnormalities per patient. Gain of 6p was the second most common abnormality (17%), and its presence was always concomitant with 6q loss. A minimal deleted region, including MIRN15A and MIRN16-1, was delineated on 13q14 in 10% of patients. Of interest, we reported biallelic deletions and/or inactivating mutations with uniparental disomy in tumor necrosis factor (TNF) receptor–associated factor 3 and TNFα-induced protein 3, two negative regulators of the nuclear factor-κB (NF-κB) signaling pathway. Furthermore, we confirmed the association between TRAF3 inactivation and increased transcriptional activity of NF-κB target genes. Mutational activation of the NF-κB pathway, which is normally activated by ligand receptor interactions within the BM microenvironment, highlights its biological importance, and suggests a therapeutic role for inhibitors of NF-κB pathway activation in the treatment of WM. [Cancer Res 2009;69(8):3579–88]

Abstract Purpose: We have previously mapped a major susceptibility locus influencing familial lung cancer risk to chromosome 6q23-25. However, the causal gene at this locus remains undetermined. In this study, we further refined this locus to identify a single candidate gene, by fine mapping using microsatellite markers and association studies using high-density single nucleotide polymorphisms (SNP). Experimental Design: Six multigenerational families with five or more affected members were chosen for fine-mapping the 6q linkage region using microsatellite markers. For association mapping, we genotyped 24 6q-linked cases and 72 unrelated noncancer controls from the Genetic Epidemiology of Lung Cancer Consortium resources using the Affymetrix 500K chipset. Significant associations were validated in two independent familial lung cancer populations: 226 familial lung cases and 313 controls from the Genetic Epidemiology of Lung Cancer Consortium, and 154 familial cases and 325 controls from Mayo Clinic. Each familial case was chosen from one high-risk lung cancer family that has three or more affected members. Results: A region-wide scan across 6q23-25 found significant association between lung cancer susceptibility and three single nucleotide polymorphisms in the first intron of the RGS17 gene. This association was further confirmed in two independent familial lung cancer populations. By quantitative real-time PCR analysis of matched tumor and normal human tissues, we found that RGS17 transcript accumulation is highly and consistently increased in sporadic lung cancers. Human lung tumor cell proliferation and tumorigenesis in nude mice are inhibited upon knockdown of RGS17 levels. Conclusion: RGS17 is a major candidate for the familial lung cancer susceptibility locus on chromosome 6q23-25.

Objective: Endoleaks are critical complications of endovascular abdominal aortic aneurysm repair (EVAR). This study sought to determine the frequency and nature of intraoperative endoleaks and their impact on postoperative endoleak-related events. Methods: A retrospective chart review was performed of all patients who underwent EVAR at our institution. The impact of intraoperative endoleaks on postoperative endoleak rates and endoleak-related reintervention rates were assessed. Results: From December 18, 1996, to May 21, 2003, 241 patients underwent EVAR. An endoleak was observed during 126 (52.3%) procedures. Type I endoleaks were observed in 63 (26.1%) cases: 35 proximal and 31 distal endoleaks (3 cases at both attachments). Angioplasty, additional cuff placement, or stenting corrected 59 (89.4%) of these endoleaks. A total of 71 type II intraoperative endoleaks (29.5%) and 8 type IV endoleaks (3.3%) were observed without any attempted corrective maneuvers. Ten type III endoleaks (4.2%) occurred but all resolved with angioplasty or additional cuff placement. In all, 86 (35.7%) endoleaks persisted on completion angiogram. Patients with a type I or type II intraoperative endoleak were more likely to have an endoleak at 1.5 years (31.4% vs. 21.6%, P = .018). Reinterventions were required more often after an intraoperative type I endoleak (10% vs. 4%, P = .003). Patients with intraoperative endoleaks demonstrated a trend toward less postoperative aneurysm diameter reduction at 2 years (43.8% vs. 74.5%, P = .104). Conclusion: The presence of a type I or a type II endoleak during EVAR significantly increases the likelihood of a postoperative endoleak and should prompt a high degree of suspicion during follow-up.

Purpose Irinotecan plus cisplatin (IP) improved survival over etoposide plus cisplatin (EP) in Japanese patients with extensive-stage small-cell lung cancer (E-SCLC). To confirm those results and discern the potential role of population-related pharmacogenomics (PG) in outcomes, we conducted a large randomized trial of identical design to the Japanese trial in North American patients with E-SCLC. Patients and Methods Patients were randomly assigned to IP (irinotecan 60 mg/m2 on days 1, 8, and 15; cisplatin 60 mg/m2 day 1, every 4 weeks) or EP (etoposide 100 mg/m2 on days 1 through 3; cisplatin 80 mg/m2 day 1, every 3 weeks). Blood specimens for genomic DNA analysis were collected before random assignment in 169 patients. Results Of 671 patients, 651 were eligible (324 and 327 patients in the IP and EP arms, respectively). Response rates with IP and EP were 60% and 57%, respectively (P = .56). Median progression-free survival for IP and EP was 5.8 and 5.2 months, respectively (P = .07). Median overall survival for IP and EP was 9.9 and 9.1 months, respectively (P = .71). Severe diarrhea was more common with IP (19% v 3%); severe neutropenia and thrombocytopenia were higher with EP versus IP (68% v 33% and 15% v 4%, respectively). PG analysis showed that ABCB1 (C3435T)T/T (membrane transport) was associated with IP-related diarrhea; UGT1A1 (G-3156A)A/A (drug metabolism) was associated with IP-related neutropenia. Conclusion This large North American trial failed to confirm the previously reported survival benefit observed with IP in Japanese patients. Both regimens produced comparable efficacy, with less hematologic and greater gastrointestinal toxicity with IP. These results emphasize the potential importance of PG in interpreting trials of cancer therapy.

Membranes flex with changes in transmembrane potential as a result of changes in interfacial tension, the Lippman effect. We studied the membrane electromotility of Shaker K + -transfected HEK-293 cells in real time by using combined patch-clamp atomic force microscopy. In the voltage range where the channels were closed, Shaker expression had little effect on electromotility relative to wild-type cells. Depolarization between −120 and −40 mV resulted in a linear upward cantilever deflection equivalent to an increase in membrane tension. However, when depolarized sufficiently for channel opening, the electromotility saturated and only recovered over 10 s of milliseconds. This remarkable loss of motility was associated with channel opening, not ionic flux or movement of the voltage sensors. The IL mutant of Shaker , in which the voltage dependence of channel opening but not sensor movement is shifted to more positive potentials, caused the loss of electromotility saturation also to shift to more positive potentials. The temporary loss of electromotility associated with channel opening is probably caused by local buckling of the bilayer as the inner half of the channel expands as expected from X-ray structural data.

Purpose To assess whether trastuzumab (H) with radiotherapy (RT) increases adverse events (AEs) after breast-conserving surgery or mastectomy. Patients and Methods Patients with early-stage resected human epidermal growth factor receptor 2 (HER-2) –positive breast cancer (BC) were randomly assigned to doxorubicin (A) and cyclophosphamide (C), followed by weekly paclitaxel (T; AC-T-H or AC-TH-H). RT criteria (with or without nodal RT) were postlumpectomy breast or (optional) postmastectomy chest wall. RT of internal mammary nodes was prohibited. RT commenced within 5 weeks after T, concurrently with H. Analysis included 1,503 irradiated patients for RT-associated AEs across treatment arms. Rates of cardiac events (CEs) with and without RT were compared within arms. Results No significant differences among arms were found in incidence of acute skin reaction, pneumonitis, dyspnea, cough, dysphagia, or neutropenia. A significant difference occurred in incidence of leukopenia, with higher rates for AC-T-H versus AC-T (odds ratio = 1.89; 95% CI, 1.25 to 2.88). At a median follow-up of 3.7 years (range, 0 to 6.5 years), RT with H did not increase relative frequency of CEs regardless of treatment side. The cumulative incidence of CEs with AC-T-H was 2.7% with or without RT. With AC-TH-H, the cumulative incidence was 1.7% v 5.9% with or without RT, respectively. Conclusion Concurrent adjuvant RT and H for early-stage BC was not associated with increased acute AEs. Further follow-up is required to assess late AEs.

Objective: The primary aim of this prospective study was to examine the role of several aspects of spirituality in maintaining abstinence from alcohol for one year in persons treated for alcohol dependence. The roles of alcohol abstinence self-efficacy and Alcoholics Anonymous affiliation were also examined. Method: Seventy-four adults with alcohol dependence who had completed a three-week outpatient addiction program participated in this study. Instruments used included the Spiritual Well-Being Scale, Duke Religion Index, Brief Religious Coping Scale, Alcohol Abstinence Self-Efficacy Scale, and Alcoholics Anonymous Affiliation Scale. Abstinence data was collected from participants and collaterals three, six, and twelve months after treatment discharge. Demographics, discharge measures, and the change in scores from admission to discharge were compared between those with and without 12-month alcohol abstinence using logistic regression or Fisher's exact tests. Results: Twenty-eight participants were categorized as continuously abstinent for one year. The strongest associations between 12 month abstinence and the variables of interest were discharge scores of abstinence self-efficacy and existential well-being, and increases during treatment in scores of private spiritual practices. Increased age demonstrated a significant association with positive outcome. Conclusion: The associations of private spiritual practices, existential well-being, and abstinence self-efficacy with one year of continuous abstinence following treatment discharge suggest the importance of addressing issues related to these variables during alcoholism treatment. More research is needed to understand the role of these variables in promoting and maintaining abstinence and to determine whether or not a related intervention would improve abstinence rates.