Association of tobacco (T) use with risk of distant metastases (DM), tumor recurrence, and death in patients (pts) with HPV-positive (+) squamous cell cancer of the oropharynx (SCCOP)

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Background: Chemoradiation (CRT) for HPV (+) SCCOP is associated with a more favorable prognosis than HPV-negative (-) SCCOP. However, the interaction of HPV and T in terms of etiology and disease progression remains unclear. HPV (+) SCCOP pts were prospectively studied to determine if T use was a key variable in discriminating which pts would develop DM, locoregional recurrences (LR), or second primaries (SP). Methods: From 1999–2007, 124 pts with stage III/IV SCCOP were enrolled in one of two CRT trials. Tumor specimens were analyzed for HPV presence and type. Use of T, determined via self-reporting and chart review, was recorded as both continuous (number of pack-yrs) and categorical (never, former, and current) variables. Former T users were subdivided into an early cessation group (quit ≥ 20 yrs prior to diagnosis) and a late cessation group (quit < 20 yrs prior to diagnosis). T use and HPV status were analyzed with respect to survival & the development of DM, LR, or SP. Results: Of the 124 pts, 100 (81%) were HPV (+), 22 of which developed disease progression (22%). Twenty-four were HPV (-), 12 of which had disease progression (50%). Seventeen of 124 pts (14%) developed DM [12 HPV (+), 5 HPV (-)]. Nine of 124 (7%) developed LR [5 HPV (+), 4 HPV (-)], and 8 of 124 (7%) developed SP [5 HPV (+), 3 HPV (-)]. Thirty-two HPV (+) pts were never-T users, 88% (28/32) of which remain alive with no evidence of disease; 3 died from other causes and 1 died of lung metastases from SCCOP. Sixty-eight were HPV (+) and had T exposure. Of 46 former T users, 37/46 (80%) are living. Twenty were HPV (+) and in the early cessation group, 35% (7/20) of which had disease progression [3 LR, 3 DM, 1 SP]. Twenty-six HPV (+) pts were former T users in the late cessation group, 11% (3/26) of which had disease progression [2 DM, 1 SP]. Of 22 HPV (+) current T users, 68% (15/22) are alive and 36% (8/22) have developed disease progression. Seventeen of the 24 HPV (-) pts were current T users, 47% (8/17) of which developed disease progression. Conclusions: Never-T users with HPV-positive SCCOP have improved survival & reduced risk of disease progression compared to HPV (+) & HPV (-) former & current T users.

No significant financial relationships to disclose.

Testicular sertoli cells protect islet beta-cells from autoimmune destruction in NOD mice by a transforming growth factor-beta1-dependent mechanism

Testicular Sertoli cells protect pancreatic islet grafts from allo- and autoimmune destruction; however, the mechanism(s) of protection is unclear. The aim of this study was to determine whether Fas ligand (FasL) and/or transforming growth factor (TGF)-beta, immunoregulatory proteins produced by Sertoli cells, might mediate the protective effects of these cells against autoimmune destruction of islet beta-cells. Sertoli cells were purified from testes of NOD mice and implanted under the right renal capsule of diabetic NOD mice, whereas NOD islets were implanted under the left renal capsule. Of the mice that received islet and Sertoli cells grafts, 64% (9 of 14) remained normoglycemic at 60 days posttransplantation compared with 0% (0 of 6) of the mice that received islet grafts alone. Immunohistochemical examination of Sertoli cell grafts in normoglycemic mice revealed that TGF-beta1 expression by Sertoli cells remained high, whereas FasL expression by Sertoli cells decreased progressively posttransplantation. Also, plasma levels of TGF-beta1 were significantly elevated in mice that received Sertoli cells and islet grafts, and anti-TGF-beta1 antibody administration completely abrogated the protective effect of Sertoli cells on islet graft survival, whereas anti-FasL antibody did not. Islet graft destruction in anti-TGF-beta1-treated mice was associated with increases in interferon (IFN)-gamma-producing cells and decreases in interleukin (IL)-4-producing cells in the islet grafts. We conclude that 1) Sertoli cell production of TGF-beta1, not FasL, protects islet beta-cells from autoimmune destruction and 2) TGF-beta1 diverts islet-infiltrating cells from a beta-cell-destructive (IFN-gamma+) phenotype to a nondestructive (IL-4+) phenotype.

RasGRP links T-cell receptor signaling to Ras

Stimulation of the T-cell receptor (TCR) alters a number of intracellular signaling pathways including one that involves protein tyrosine kinases, phospholipase C-gamma1 (PLC-gamma1), diacylglycerol (DAG), and calcium messengers. By a divergent pathway, TCR-stimulated protein tyrosine kinase activity is thought to result independently in recruitment of the Ras activator Sos to the plasma membrane, leading to Ras activation. Here we show that RasGRP, a Ras activator that contains calcium-binding EF hands and a DAG-binding domain, is expressed in T cells. A PLC-gamma1 inhibitor diminished activation of Ras following TCR stimulation. Membranes from TCR-stimulated Jurkat T cells exhibited increased RasGRP and increased Ras-guanyl nucleotide association activity that was inhibited by antibodies directed against RasGRP. Overexpression of RasGRP in T cells enhanced TCR-Ras-Erk signaling and augmented interleukin-2 secretion in response to calcium ionophore plus DAG analogues phorbol ester myristate or bryostatin-1. Thus, RasGRP links TCR and PLC-gamma1 to Ras-Erk signaling, a pathway amenable to pharmacologic manipulation.

A novel immunosuppressive factor in bovine colostrum blocks activation of the interleukin 2 gene enhancer at the NFAT site

A factor in bovine colostrum (colostrum inhibitory factor, CIF) inhibits interleukin 2 (IL2) production in activated T helper cells by blocking the accumulation of IL2 mRNA. To determine whether CIF blocks at the level of IL2 transcription, we introduced reporter plasmids into the human T leukemia cell line Jurkat by transient transfection. These contained the luciferase gene under the control of either the human IL2 upstream enhancer region (segments -326 to +45) or three repeats of the NFAT element contained within it (segments -255 to -285). Expression of luciferase in these cells was induced by phorbol myristate acetate plus a calcium ionophore. CIF inhibited induction of either construct as did cyclosporine, which is known to block activation of the NFAT element. CIF failed to inhibit several other enhancer elements. The NFAT-controlled luciferase gene system distinguishes CIF from other T cell inhibitory activities present in colostrum, in particular, TGF beta 1 and TGF beta 2 and the glucocorticoids. Stably transfected Jurkat cells behaved similarly to the transiently transfected ones with respect to inhibition by CIF and cyclosporine. The NFAT-luc assay is a useful technique for the rapid, sensitive measurement of CIF or other immunosuppressants with a similar mode of action.

Successful embryo transfer following artificial insemination of superovulated fallow deer (Dama dama)

Thirty-four European fallow deer (Dama dama dama) were randomly allocated into embryo donor (n = 12) or embryo recipient (n = 22) groups. All does were treated with controlled internal drug release (CIDR) devices for 14 days. Animals in the embryo donor group were further treated with 200 I.U. pregnant mare serum gonadotrophin (PMSG) and 0.5 units ovine follicle-stimulating hormone (FSH). PMSG was administered 72 h before withdrawal of CIDR devices and FSH was given in eight 0.063 unit injections at 12-hourly intervals starting at the time of PMSG administration. All embryo donor animals were inseminated, by laparoscopy in both uterine horns, 36 h after withdrawal of CIDR devices with 25 x 10(6) fresh spermatozoa collected from Mesopotamian fallow deer (Dama dama mesopotamica). Embryos were recovered by laparotomy on Day 3 (n = 6) or Day 6 (n = 6) after withdrawal of CIDR devices and the ovarian response was determined. In total, 22 embryos were transferred into the oviduct (2-4-cell stage, n = 14) or uterine horn (morula stage, n = 8) on Day 3 or Day 6 after withdrawal of CIDR devices respectively. The overall means (+/- s.e.m.) of total follicular response and corpora lutea were 24.2 +/- 3.5 and 14.1 +/- 3.6 respectively. The mean number of large unruptured follicles was higher on Day 6 than on Day 3 (13.5 +/- 2.9 v. 6.7 +/- 1.3, P < 0.05). The overall embryo recovery rate was 45.8%. There was no difference in pregnancy rate following transfer of embryos on either Day 3 or Day 6 (7/14 v. 5/8 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)