The BET bromodomain inhibitor JQ1 suppresses growth of pancreatic ductal adenocarcinoma in patient-derived xenograft models

The primary aim of this study was to evaluate the antitumor efficacy of the bromodomain inhibitor JQ1 in pancreatic ductal adenocarcinoma (PDAC) patient-derived xenograft (tumorgraft) models. A secondary aim of the study was to evaluate whether JQ1 decreases expression of the oncogene c-Myc in PDAC tumors, as has been reported for other tumor types. We used five PDAC tumorgraft models that retain specific characteristics of tumors of origin to evaluate the antitumor efficacy of JQ1. Tumor-bearing mice were treated with JQ1 (50 mg/kg daily for 21 or 28 days). Expression analyses were performed with tumors harvested from host mice after treatment with JQ1 or vehicle control. An nCounter PanCancer Pathways Panel (NanoString Technologies) of 230 cancer-related genes was used to identify gene products affected by JQ1. Quantitative RT-PCR, immunohistochemistry and immunoblots were carried out to confirm that changes in RNA expression reflected changes in protein expression. JQ1 inhibited the growth of all five tumorgraft models (P<0.05), each of which harbors a KRAS mutation; but induced no consistent change in expression of c-Myc protein. Expression profiling identified CDC25B, a regulator of cell cycle progression, as one of the three RNA species (TIMP3, LMO2 and CDC25B) downregulated by JQ1 (P<0.05). Inhibition of tumor progression was more closely related to decreased expression of nuclear CDC25B than to changes in c-Myc expression. JQ1 and other agents that inhibit the function of proteins with bromodomains merit further investigation for treating PDAC tumors. Work is ongoing in our laboratory to identify effective drug combinations that include JQ1.

Hypoxia promotes fibrogenesis in human renal fibroblasts

BACKGROUND

The mechanisms underlying progressive renal fibrosis are unknown, but the common association of fibrosis and microvascular loss suggests that hypoxia per se may be a fibrogenic stimulus.

METHODS

To determine whether human renal fibroblasts (HRFs), the primary matrix-producing cells in the tubulointerstitium, possess oxygen-sensitive responses relevant to fibrogenesis, cells were exposed to 1% O2 in vitro.

RESULTS

Hypoxia simultaneously stimulated extracellular matrix synthesis and suppressed turnover with increased production of collagen alpha1(I) (Coll-I), decreased expression of collagenase, and increased tissue inhibitor of metalloproteinase (TIMP)-1. These effects are time dependent, require new RNA and protein synthesis, and are specific to hypoxia. The changes in Coll-I and TIMP-1 gene expression involve a heme-protein O2 sensor and protein kinase- and tyrosine kinase-mediated signaling. Although hypoxia induced transforming growth factor-beta1 (TGF-beta1), neutralizing anti-TGF-beta1-antibody did not block hypoxia-induced Coll-I and TIMP-1 mRNA expression. Furthermore, hypoxic-cell conditioned-medium had no effect on the expression of these mRNAs in naive fibroblasts, suggesting direct effects on gene transcription. Transient transfections identified a hypoxia response element (HRE) in the TIMP-1 promoter and demonstrated HIF-1-dependent promoter activation by decreased ambient pO2.

CONCLUSIONS

These data suggest that hypoxia co-ordinately up-regulates matrix production and decreases turnover in renal fibroblasts. The results support a role for hypoxia in the pathogenesis of fibrosis and provide evidence for novel, direct hypoxic effects on the expression of genes involved in fibrogenesis.

Children's hedonic response to the smell of alcohol: effects of parental drinking habits

BACKGROUND

Previous research in our laboratory revealed that during the first year of life, infants who had more exposure to alcohol, as inferred from questionnaires about parental alcoholism and alcohol intake, mouthed an ethanol-scented toy more compared with less exposed infants. The present study focused on older children (3.8-6.0 years) to determine whether their hedonic response to the odor of alcohol was related to the drinking habits of their parents.

METHODS

Age-appropriate, game-like tasks that were fun for children and minimized the impact of language development were used to examine their preferences and identification of a variety of odors, one of which was beer.

RESULTS

The children's preference for the odor of beer varied as a function of the escape drinking of their mothers alone or both parents. That is, children who lived in a household in which one or both parents drank alcohol to escape were significantly more likely to dislike the odor bottle that contained alcohol when compared with children whose parents did not drink to escape. This difference between the groups was odor specific. Additional analyses also revealed that the fathers of children who rejected the beer odor reported drinking significantly more than the fathers of those who liked the odor.

CONCLUSIONS

These findings suggest that some early learning about alcohol is based on sensory experiences and anchor it to children's experiences at home and the emotional context in which their parents experience alcohol.

Bronchoalveolar lavage fluid evaluation in rheumatoid arthritis

Rheumatoid arthritis (RA), a systemic disorder of unknown cause, is associated with a variety of well-recognized pulmonary abnormalities including interstitial lung disease. To investigate possible pathogenic events in this disorder, we performed bronchoalveolar lavage (BAL) in 24 patients with classic or definite RA. Using radiographic and physiologic parameters as well as BAL cell differentials, 3 distinct groups emerged. Group I consisted of 9 patients with evidence of clinical interstitial lung involvement. Group II consisted of 5 patients without evidence of clinical interstitial lung disease (normal chest roentgenogram and functional testing) but who had abnormal BAL cellular differentials. The 10 remaining patients (Group III) had no evidence of clinical interstitial lung disease and had normal BAL cell differentials. Bronchoalveolar lavage in Group I had a significantly increased percentage of neutrophils (12.4 +/- 4.2; p less than 0.05) compared with Group II (2.4 +/- 0.8) and Group III (2.9 +/- 0.6). All patients in Group II had elevated BAL lymphocytes (24.4 +/- 6.4) compared with Group I (10.1 +/- 3.8; p greater than 0.05) and Group III (5.4 +/- 0.7; p less than 0.01). Both Groups I and II had detectable IgM in BAL (0.02 +/- 0.01 and 0.04 +/- 0.02 mg/mg of albumin, respectively), whereas Group III patients and normal control subjects did not (p less than 0.01). There was a marked reduction in BAL T-lymphocyte Leu 3/Leu 2A (helper/suppressor) cell ratios in Group I (0.92 +/- 0.02; p less than 0.05) compared with Group II (2.6 +/- 0.6) and Group III (1.6 +/- 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)