Impact of Marijuana Legalization on Opioid Utilization in Patients Diagnosed with Pain.

BACKGROUND: Given efforts to reduce opioid use, and because marijuana potentially offers a lower-risk alternative for treating chronic pain, there is interest in understanding the public health impact of marijuana legalization on opioid-related outcomes. OBJECTIVE: Assess the impact of recreational and medical marijuana legalization on opioid utilization among patients receiving pharmacotherapy for pain. DESIGN: Retrospective claims-based study of commercially insured patients continuously eligible for pharmacy and medical benefits from July 8, 2014 to June 30, 2017. Index pain prescription period was defined between January 8, 2015 and June 30, 2015, and longer-term opioid use examined during 2-year follow-up. Marijuana state policy on July 1, 2015, was assigned: none; medical only; or medical and recreational. PARTICIPANTS: Patients aged 18-62 without cancer diagnosis. MAIN MEASURES: Patient receiving (1) opioid at index; (2) > 7 days' supply of index opioid; (3) opioid during follow-up; and (4) ≥ 90 days' opioid supply during follow-up. Multivariable regression assessed associations between opioid utilization and state marijuana policy, adjusting for age, gender, overall disease burden, mental health treatment, concomitant use of benzodiazepine or muscle relaxant, and previous pain prescription. KEY RESULTS: Of 141,711 patients, 80,955 (57.1%) resided in states with no policy; 56,494 (39.9%) with medical-only; and 4262 (3.0%) with medical and recreational. Patients in states with both policies were more likely to receive an index opioid (aOR = 1.72, 95% CI = 1.61-1.85; aOR = 1.90, 95% CI = 1.77-2.03; P < 0.001) but less likely to receive > 7 days' index supply (aOR = 0.84, 95% CI = 0.77-0.91; aOR = 0.76, 95% CI = 0.70-0.83; P < 0.001) than patients in states with no policy or medical-only, respectively. Those in states with both policies were more likely to receive a follow-up opioid (aOR = 1.87, 95% CI = 1.71-2.05; aOR = 2.20, 95% CI = 2.01-2.42; P < 0.001) than those in states with no policy or medical-only, respectively, and more likely to receive ≥ 90 cumulative follow-up opioid days' supply (aOR = 1.18, 95% CI = 1.07-1.29; P < 0.001) than those in states with no policy. CONCLUSIONS: Our analysis does not support the supposition that access to marijuana lowers use of chronic opioids for pain.

Global profiling of prolactin-modulated transcripts in breast cancer in vivo.

BACKGROUND: Prolactin (PRL) is essential for normal mammary gland development. PRL promotes mammary tumor formation in rodents and elevated serum prolactin is associated with increased risk of estrogen-receptor positive breast cancer in women. On the other hand, PRL may also exert pro-differentiation effects and act to suppress invasive features of established breast cancer. Previously published limited global transcript profiling analyses of prolactin-regulated gene expression in human breast cancer cells have exclusively been performed in vitro. The present study aimed to shed new light on how PRL modulates estrogen receptor (ER)-positive breast cancer through global transcript profiling of a human breast cancer xenograft model in vivo. METHODS: The prolactin-responsive human T47D breast cancer cell line was xenotransplanted into nude mice and global transcript profiling was carried out following treatment with or without human PRL for 48 h. A subset of PRL-modulated transcripts was further validated using qRT-PCR and immunohistochemistry. RESULTS: The in vivo analyses identified 130 PRL-modulated transcripts, 75 upregulated and 55 downregulated, based on fold change >1.6 and P-value <0.05. From this initial panel of transcripts, a subset of 18 transcripts with established breast cancer-relevance were selected and validated by qRT-PCR. Some but not all of the transcripts were also PRL-modulated in vitro. The selected PRL-modulated transcripts were tested for dependence on Stat5, Jak1 or Jak2 activation, and for co-regulation by 17ß-estradiol (E2). The protein encoded by one of the PRL-regulated transcripts, PTHrP, was examined in a panel of 92 human breast cancers and found by in situ quantitative immunofluorescence analysis to be highly positively correlated with nuclear localized and tyrosine phosphorylated Stat5. Gene Ontology analysis revealed that PRL-upregulated genes were enriched in pathways involved in differentiation. Finally, a gene signature based on PRL-upregulated genes was associated with prolonged relapse-free and metastasis-free survival in breast cancer patients. CONCLUSIONS: This global analysis identified and validated a panel of PRL-modulated transcripts in an ER-positive human breast cancer xenotransplant model, which may have value as markers of relapse-free and metastasis-free survival. Gene products identified in the present study may facilitate ongoing deciphering of the pleiotropic effects of PRL on human breast cancer.

Prolactin inhibits BCL6 expression in breast cancer through a Stat5a-dependent mechanism.

BCL6 is a transcriptional repressor that recognizes DNA target sequences similar to those recognized by signal transducer and activator of transcriptions 5 (Stat5). BCL6 disrupts differentiation of breast epithelia, is downregulated during lactation, and is upregulated in poorly differentiated breast cancer. In contrast, Stat5a mediates prolactin-induced differentiation of mammary epithelia, and loss of Stat5 signaling in human breast cancer is associated with undifferentiated histology and poor prognosis. Here, we identify the mammary cell growth factor prolactin as a potent suppressor of BCL6 protein expression in human breast cancer through a mechanism that requires Stat5a, but not prolactin-activated Stat5b, MEK-ERK, or PI3K-AKT pathways. Prolactin rapidly suppressed BCL6 mRNA in T47D, MCF7, ZR75.1, and SKBr3 breast cancer cell lines, followed by prolonged reduction of BCL6 protein levels within 3 hours. Prolactin suppression of BCL6 was enhanced by overexpression of Stat5a but not Stat5b, was mimicked by constitutively active Stat5a, but did not require the transactivation domain of Stat5a. Stat5 chromatin immunoprecipitation demonstrated physical interaction with a BCL6 gene regulatory region, and BCL6 transcript repression required histone deacetylase activity based on sensitivity to trichostatin A. Functionally, BCL6 overexpression disrupted prolactin induction of Stat5 reporter genes. Prolactin suppression of BCL6 was extended to xenotransplant tumors in nude mice in vivo and to freshly isolated human breast cancer explants ex vivo. Quantitative immunohistochemistry revealed elevated BCL6 in high-grade and metastatic breast cancer compared with ductal carcinoma in situ and nonmalignant breast, and cellular BCL6 protein levels correlated negatively with nuclear Stat5a (r = -0.52; P < 0.001) but not with Stat5b. Loss of prolactin-Stat5a signaling and concomitant upregulation of BCL6 may represent a regulatory switch facilitating undifferentiated histology and poor prognosis of breast cancer.

Coactivation of janus tyrosine kinase (Jak)1 positively modulates prolactin-Jak2 signaling in breast cancer: recruitment of ERK and signal transducer and activator of transcription (Stat)3 and enhancement of Akt and Stat5a/b pathways.

Prolactin (PRL) receptors (PRLRs) have been considered selective activators of Janus tyrosine kinase (Jak)2 but not Jak1, Jak3, or Tyk2. We now report marked PRL-induced tyrosine phosphorylation of Jak1, in addition to Jak2, in a series of human breast cancer cell lines, including T47D, MCF7, and SKBR3. In contrast, PRL did not activate Jak1 in immortalized, noncancerous breast epithelial lines HC11, MCF10A, ME16C, and HBL-100, or in CWR22Rv1 prostate cancer cells or MDA-MB-231 breast cancer cells. However, introduction of exogenous PRLR into MCF10A, ME16C, or MDA-MB-231 cells reconstituted both PRL-Jak1 and PRL-Jak2 signals. In vitro kinase assays verified that PRL stimulated enzymatic activity of Jak1 in T47D cells, and PRL activated Jak1 and Jak2 with indistinguishable time and dose kinetics. Relative Jak2 deficiency did not cause PRLR activation of Jak1, because overexpression of Jak2 did not interfere with PRL activation of Jak1. Instead, PRL activated Jak1 through a Jak2-dependent mechanism, based on disruption of PRL activation of Jak1 after Jak2 suppression by 1) lentiviral delivery of Jak2 short hairpin RNA, 2) adenoviral delivery of dominant-negative Jak2, and 3) AG490 pharmacological inhibition. Finally, suppression of Jak1 by lentiviral delivery of Jak1 short hairpin RNA blocked PRL activation of ERK and signal transducer and activator of transcription (Stat)3 and suppressed PRL activation of Jak2, Stat5a, Stat5b, and Akt, as well as tyrosine phosphorylation of PRLR. The data suggest that PRL activation of Jak1 represents a novel, Jak2-dependent mechanism that may serve as a regulatory switch leading to PRL activation of ERK and Stat3 pathways, while also serving to enhance PRL-induced Stat5a/b and Akt signaling.