PIK3CA dependence and sensitivity to therapeutic targeting in urothelial carcinoma.

BACKGROUND: Many urothelial carcinomas (UC) contain activating PIK3CA mutations. In telomerase-immortalized normal urothelial cells (TERT-NHUC), ectopic expression of mutant PIK3CA induces PI3K pathway activation, cell proliferation and cell migration. However, it is not clear whether advanced UC tumors are PIK3CA-dependent and whether PI3K pathway inhibition is a good therapeutic option in such cases. METHODS: We used retrovirus-mediated delivery of shRNA to knock down mutant PIK3CA in UC cell lines and assessed effects on pathway activation, cell proliferation, migration and tumorigenicity. The effect of the class I PI3K inhibitor GDC-0941 was assessed in a panel of UC cell lines with a range of known molecular alterations in the PI3K pathway. RESULTS: Specific knockdown of PIK3CA inhibited proliferation, migration, anchorage-independent growth and in vivo tumor growth of cells with PIK3CA mutations. Sensitivity to GDC-0941 was dependent on hotspot PIK3CA mutation status. Cells with rare PIK3CA mutations and co-occurring TSC1 or PTEN mutations were less sensitive. Furthermore, downstream PI3K pathway alterations in TSC1 or PTEN or co-occurring AKT1 and RAS gene mutations were associated with GDC-0941 resistance. CONCLUSIONS: Mutant PIK3CA is a potent oncogenic driver in many UC cell lines and may represent a valuable therapeutic target in advanced bladder cancer.

PIK3CA mutation spectrum in urothelial carcinoma reflects cell context-dependent signaling and phenotypic outputs.

Although activating mutations of PIK3CA are frequent in urothelial carcinoma (UC), no information is available on their specific effects in urothelial cells or the basis for the observed mutation spectrum, which has a large excess of helical domain mutations. We investigated the phenotypic and signaling consequences of hotspot and UC-specific rare PIK3CA mutations in immortalized normal human urothelial cells (NHUC) and mouse fibroblasts (NIH3T3). Our results indicate that in NHUC, rare mutant forms and all three hotspot mutant forms of PIK3CA can activate the PI3K/AKT pathway. The relative frequency at which helical domain and kinase domain mutations are found in UC is related to their potency in inducing signaling downstream of AKT and to the phenotypic effects induced in this cell type (E545K>E542K>H1047R). Helical domain mutations E542K and E545K conferred a significant proliferative advantage at confluence and under conditions of nutrient depletion, and increased cellular resistance to anoikis. Both helical and kinase domain mutants induced increased NHUC cell motility and migration towards a chemoattractant, though no significant differences were found between the mutant forms. In NIH3T3 cells, the kinase domain mutant H1047R induced high levels of AKT activation, but helical domain mutants were significantly less potent and this was reflected in their relative abilities to confer anchorage-independent growth. Our findings indicate that the effects of mutant PIK3CA are both cell type- and mutation-specific. Helical domain mutations in PIK3CA may confer a selective advantage in the urothelium in vivo by overcoming normal contact-mediated inhibitory signals and allowing proliferation in nutrient-limiting conditions. Mutant forms of PIK3CA may also stimulate intraepithelial cell movement, which could contribute to spread of cells within the urothelium.

Rural and urban problem drinkers in six Southern states.

In 1994-1997 we conducted a four-wave longitudinal study of rural and urban problem drinkers in six Southern United States states to examine rural/urban differences in predictors of service use and course of drinking. This report describes early rural/urban differences from a brief interview with over 3,000 community individuals and among 525 identified problem drinkers. Overall, we found rural/urban differences in alcohol consumption at the community level but only demographic differences among problem drinkers. Our newly developed screening interview for alcohol disorders had excellent agreement (kappa = 0.72) for lifetime disorders and good agreement (kappa = 0.53) for recent disorders against structured diagnostic interviews for DSM-IV criteria.

Does this treatment work? Validation of an outcomes module for alcohol dependence.

The purpose of this study was to evaluate the outcomes of routine care administered to alcohol-dependent inpatients. The authors sought to validate a self-administered instrument that measures the types and extent of care delivered, the outcomes of that care, and casemix characteristics that influence the outcomes of care. Seventy-eight patients who were beginning inpatient treatment for alcohol dependence were recruited; 85% were followed 5 months later to examine cross-sectional and longitudinal relationships to gold standard assessments. The self-administered module demonstrated excellent agreement with structured interview assessments of diagnosis (kappa = .81), remission (kappa = .83), and change in severity of alcohol-related problems (r = .66 to .87). Casemix variables, particularly baseline severity, predicted change in alcohol consumption and functional status. The baseline module required 20 minutes for the average patient and 5 minutes for the average clinician to complete, with less than 2% missing data. Results indicated that the module measures key constructs with sufficient precision to assist clinicians and researchers in characterizing the degree to which routine inpatient care for alcohol dependence "works" in their patient population. The entire module is in the public domain and available free of charge to interested users.

Utilization of acute inpatient services for alcohol detoxification.

This study indicates that the majority of patients admitted to VA hospitals for medical detoxification could have those services provided on an outpatient or less intensive basis. However, inpatient medical detoxification services appear to be appropriate for those alcoholics at risk for potential life-threatening complications of withdrawal such as delirium tremens, or those with concurrent associated medical conditions such as pancreatitis, gastrointestinal bleeding, or complications of cirrhosis. Data were obtained from a national random sample of hospitalizations in Department of Veterans Affairs (VA) inpatient medical and surgical units. Medical records for 144 alcoholism-related medical admissions to 35 VA medical centers were reviewed using the Appropriateness Evaluation Protocol (AEP), a clinically based utilization review instrument widely used in the private sector. The medical records for the admission and each day of medical/surgical inpatient stay were reviewed using clinical criteria for the appropriateness of acute inpatient care as opposed to lower levels of care.

Psychiatrists' compliance with nonpsychiatric consultations: does compliance affect concordance?

Utilizing a systematic methodology (The Consultation-Liaison Outcome Evaluation System), the compliance of nonpsychiatric consultations within a general hospital psychiatric unit staffed by private practitioners was assessed. Thirty-one percent of the patients received such consultations and these patients had a longer length of stay than those without a consultation. Psychiatrists were generally compliant with both medication and diagnostic recommendations; but in only half the discharge summaries was the consultant's primary medical diagnosis fully reflected. The implications of these data are discussed.

Solvent systems for intracarotid 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) infusion.

The agent, 1,3-bis(3-chloroethyl)-1-nitrosourea (BCNU), when given by arterial infusion for brain tumor chemotherapy is usually dissolved in an alcohol/saline solution. The authors compared the osmolality of and drug recovery from solvent systems of alcohol/saline, dimethyl sulfoxide (DMSO)/water, and dextrose/water. Recovery of drug was adequate from all solvent systems, although variability of drug recovery from the alcohol/saline and DMSO/water systems was greater than from the dextrose/water system. The alcohol/saline system was significantly hyperosmolar. The alcohol/saline and DMSO/water solvent systems offer no advantage over the dextrose/water system and may be associated with significant disadvantages.

Supraophthalmic carotid infusion for brain-tumor chemotherapy. Technical note.

The ocular complications of intracarotid infusion of drugs for brain-tumor chemotherapy may be eliminated by infusion of the chemotherapeutic agent into the carotid artery above the origin of the ophthalmic artery. The authors have developed a catheter that can negotiate the carotid siphon. This catheter is not balloon-tipped but incorporates a flexible tip with an expanded end to facilitate drag by flowing blood. The exit hole is placed to allow remote manipulation of the tip by hydraulic forces. Using this catheter, the authors have been consistently able to infuse the supraophthalmic carotid artery.