IMPORTANCE Individuals genetically predisposed to pancreatic cancer may benefit from early detection. Genes that predispose to pancreatic cancer and the risks of pancreatic cancer associated with mutations in these genes are not well defined. OBJECTIVE To determine whether inherited germline mutations in cancer predisposition genes are associated with increased risks of pancreatic cancer. DESIGN, SETTING, AND PARTICIPANTS Case-control analysis to identify pancreatic cancer predisposition genes; longitudinal analysis of patients with pancreatic cancer for prognosis. The study included 3030 adults diagnosed as having pancreatic cancer and enrolled in a Mayo Clinic registry between October 12, 2000, and March 31, 2016, with last follow-up on June 22, 2017. Reference controls were 123 136 individuals with exome sequence data in the public Genome Aggregation Database and 53 105 in the Exome Aggregation Consortium database. EXPOSURES Individuals were classified based on carrying a deleterious mutation in cancer predisposition genes and having a personal or family history of cancer. MAIN OUTCOMES AND MEASURES Germline mutations in coding regions of 21 cancer predisposition genes were identified by sequencing of products from a custom multiplex polymerase chain reaction–based panel; associations of genes with pancreatic cancer were assessed by comparing frequency of mutations in genes of pancreatic cancer patients with those of reference controls. RESULTS Comparing 3030 case patients with pancreatic cancer (43.2% female; 95.6% non-Hispanic white; mean age at diagnosis, 65.3 [SD, 10.7] years) with reference controls, significant associations were observed between pancreatic cancer and mutations in CDKN2A (0.3% of cases and 0.02% of controls; odds ratio [OR], 12.33; 95% CI, 5.43–25.61); TP53 (0.2% of cases and 0.02% of controls; OR, 6.70; 95% CI, 2.52–14.95); MLH1 (0.13% of cases and 0.02% of controls; OR, 6.66; 95% CI, 1.94–17.53); BRCA2 (1.9% of cases and 0.3% of controls; OR, 6.20; 95% CI, 4.62–8.17); ATM (2.3% of cases and 0.37% of controls; OR, 5.71; 95% CI, 4.38–7.33); and BRCA1 (0.6% of cases and 0.2% of controls; OR, 2.58; 95% CI, 1.54–4.05). CONCLUSIONS AND RELEVANCE In this case-control study, mutations in 6 genes associated with pancreatic cancer were found in 5.5% of all0 pancreatic cancer patients, including 7.9% of patients with a family history of pancreatic cancer and 5.2% of patients without a family history of pancreatic cancer. Further research is needed for replication in other populations.

Ral GTPases are important mediators of transformation, tumorigenesis, and cancer progression. We recently identified the metastasis-associated protein CD24, a glycosyl phosphatidyl inositol-linked surface protein, as a downstream target of Ral signaling by profiling the expression of RalA/B-depleted bladder carcinoma cells. Because CD24 is highly expressed in bladder and many other tumor types, we sought to determine if this protein plays an essential role in maintaining the malignant phenotype. Here, we show that loss of CD24 function in cell lines derived from common tumor types is associated with decreased rates of cell proliferation, clonogenicity in soft agar, changes in the actin cytoskeleton, and induction of apoptosis. Given these phenotypes, we evaluated a human bladder cancer tissue microarray by immunohistochemistry for CD24 to determine if CD24 is a prognostic cancer biomarker. Multivariate analysis showed that increased CD24 expression correlated with shorter patient disease-free survival (P = 0.07). In conclusion, we show that CD24 is a novel and functionally relevant Ral-regulated target and a potentially important prognostic marker. We suggest that these insights may lead to future therapeutic approaches that seek to eliminate CD24 function in cancer cells. (Cancer Res 2006; 66(4): 1917-22)

RalA expression in human prostate cancer is associated with cell migration and is necessary for bone metastasis. However, the downstream effectors of RalA that mediate these functions remain unclear. Here we examined cell migration after small interfering RNA-mediated depletion of Ral effectors Ral binding protein 1 (RalBP1/RLIP), exocyst complex component 2 (Sec5), and phospholipase D1 (PLD1) and found that RalBP1 and RalA depletion inhibited cell migration to a similar extent. Stable lentivirus short hairpin interfering RNA-mediated depletion of RalA and RalBP1 in PC3 human prostate cancer cells inhibited bone metastasis after intracardiac inoculation. Depletion of RalBP1 diminished orthotopic tumor growth of PC3 cells and inhibited spontaneous metastasis from this site. Interestingly, the expression of wild-type or RalA mutants deficient in RalBP1 binding was effective at rescuing the reduced metastatic capacity of RalA-depleted PC3 cells, suggesting that RalA depletion does not reduce this solely by diminished interaction with RalBP1. To determine whether the role of RalBP1 in metastasis is relevant beyond prostate cancer, we studied the requirement of RalBP1 expression in an experimental metastasis model of human bladder cancer, a tumor type with high RalBP1 expression. Depletion of RalBP1 in UMUC3 cells resulted in decreased lung colonization while having a minimal effect on subcutaneous tumor growth. Our studies are the first to suggest that the expression of RalBP1 is necessary for human cancer cell metastasis. Furthermore, we show that the requirement for RalA expression for manifestation of this phenotype is not entirely dependent on a RalA-RalBP1 interaction.

Six cyclic thiourea/urea functionalized triphenylamine-based dyes (AZ1-AZ6) containing 2-cyanoacrylic acid as an acceptor and various linkers (phenyl, biphenyl, and bithiophene) were synthesized. They exhibited high photovoltaic performance owing to an improved short-circuit photocurrent density (J(sc)) and open-circuit voltage (V(oc)). Among them, AZ6 bearing a cyclic thiourea group and bithiophene linker showed the highest power conversion efficiency (PCE) up to 7.29%, which was comparable to that of N719 (PCE = 7.36%).

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is frequently inactivated in metastatic prostate cancer, yet the molecular consequences of this and their association with the metastatic phenotype are incompletely understood. We performed transcriptomic analysis and identified genes altered by conditional PTEN reexpression in C4-2, a human metastatic prostate cancer cell line with inactive PTEN. PTEN-regulated genes were disproportionately represented among genes altered in human prostate cancer progression and metastasis but not among those associated with tumorigenesis. From the former set, we identified two novel putative PTEN targets, cdc6 and cyclin E2, which were overexpressed in metastatic human prostate cancer and up-regulated as a function of PTEN depletion in poorly metastatic DU145 human prostate cancer cells harboring a wild type PTEN. Inhibition of cdc6 and cyclin E2 levels as a consequence of PTEN expression was associated with cell cycle G(1) arrest, whereas use of PTEN activity mutants revealed that regulation of these genes was dependent on PTEN lipid phosphatase activity. Computational and promoter-reporter evaluations implicated the E2F transcription factor in PTEN regulation of cdc6 and cyclin E2 expression. Our results suggest a hypothetical model whereby PTEN loss upregulates cell cycle genes such as cdc6 and cyclin E2 that in turn promote metastatic colonization at distant sites.

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PTEN induction confers androgen independent CaP cells enhanced responsiveness to the anti-proliferative effects of anti-androgens and this action may involve non-AR mediated effects.

Little is known about the role of the tumor suppressor gene phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in prostate cancer bone metastasis. To explore this, we used a pTetOn PTEN cell line in which PTEN expression was reconstituted in a PTEN-null bone metastatic human prostate cancer cell line, LnCaP-C4-2. We found that C4-2 cells selectively migrated toward conditioned medium from primary mouse calvaria cells compared with that derived from lung fibroblasts. Further evaluation with conditioned medium from an established mouse calvaria osteoblast cell line and control non-osteoblast cell line indicates that osteoblastic characteristics convey this specific migration to C4-2 cells. We evaluated promiscuously metastatic PC-3 prostate as well as T24T and UMUC-3 bladder cells and found they did not have a specific migratory response to calvaria-conditioned medium as did C4-2. Induction of PTEN expression inhibited the motility of C4-2 cells toward calvaria-conditioned medium but had no effect on migration toward lung-conditioned medium and this inhibitory effect was dependent on the PTEN lipid phosphatase activity. Calvaria- but not lung-conditioned medium induced activation of the small GTPase Rac1. Constitutively active Rac1 but not focal adhesion kinase or Cdc42 could rescue cells from the inhibitory effect of PTEN on cell migration and PTEN induction was observed to inhibit Rac1 activation in response to calvaria-conditioned medium. Our results support the notion that loss of PTEN function in human prostate cancer may specifically facilitate bone rather than other organ metastasis and suggest that Rac1, as a PTEN effector, may contribute to this metastatic tropism.