Association of body mass index and inflammatory dietary pattern with breast cancer pathologic and genomic immunophenotype in the nurses' health study

BACKGROUND

Breast tumor immune infiltration is clearly associated with improved treatment response and outcomes in breast cancer. However, modifiable patient factors associated with breast cancer immune infiltrates are poorly understood. The Nurses' Health Study (NHS) offers a unique cohort to study immune gene expression in tumor and adjacent normal breast tissue, immune cell-specific immunohistochemistry (IHC), and patient exposures. We evaluated the association of body mass index (BMI) change since age 18, physical activity, and the empirical dietary inflammatory pattern (EDIP) score, all implicated in systemic inflammation, with immune cell-specific expression scores.

METHODS

This population-based, prospective observational study evaluated 882 NHS and NHSII participants diagnosed with invasive breast cancer with detailed exposure and gene expression data. Of these, 262 women (training cohort) had breast tumor IHC for four classic immune cell markers (CD8, CD4, CD20, and CD163). Four immune cell-specific scores were derived via lasso regression using 105 published immune expression signatures' association with IHC. In the remaining 620 patient evaluation cohort, we evaluated association of each immune cell-specific score as outcomes, with BMI change since age 18, physical activity, and EDIP score as predictors, using multivariable-adjusted linear regression.

RESULTS

Among women with paired expression/IHC data from breast tumor tissue, we identified robust correlation between novel immune cell-specific expression scores and IHC. BMI change since age 18 was positively associated with CD4+ (β = 0.16; p = 0.009), and CD163 novel immune scores (β = 0.14; p = 0.04) in multivariable analyses. In other words, for each 10 unit (kg/m2) increase in BMI, the percentage of cells positive for CD4 and CD163 increased 1.6% and 1.4%, respectively. Neither physical activity nor EDIP was significantly associated with any immune cell-specific expression score in multivariable analyses.

CONCLUSIONS

BMI change since age 18 was positively associated with novel CD4+ and CD163+ cell scores in breast cancer, supporting further study of the effect of modifiable factors like weight gain on the immune microenvironment.

Effects of serum-free in vitro maturation of bovine oocytes on subsequent embryo development and cell allocation in two developmental stages of day 7 blastocysts

Maturation of oocytes and the subsequent outcome of the in vitro production (IVP) are affected by the composition of in vitro maturation (IVM) medium. To determine the use of serum interfering with effects of single molecules, we aimed at developing simplified IVM medium. The experimental IVM media were: (1) M199-medium supplemented with hormones and serum (control), (2) as 1 but serum was substituted with fatty acid-free serum albumin (FAFBSA) and (3) M199-medium without hormonal and serum supplementation (M199). The quality of embryos was assessed on day 7 by morphology and cryotolerance, as well as by Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling (TUNEL) and differential staining. Results showed that the nuclear maturation was suppressed in M199 group alone. Embryo cleavage and development rates, and the proportion of quality 1 blastocysts were lower in the FAFBSA and M199 groups compared to the control. Differences in the cell allocation of fresh embryos were observed at the blastocyst stage, but not at the expanded blastocyst stage. The control group blastocysts had larger number of cells allocated to the inner cell mass (ICM), and the FAFBSA group blastocysts larger apoptotic cell proportion compared to the blastocysts derived from other groups. After cryopreservation, the reduction of ICM proportion and increase of apoptotic cell proportion of embryos were equal between the experimental groups. In conclusion, exclusion of serum from the IVM media reduces embryo development and may cause perturbations in blastocyst development. Differences in the cell allocation of blastocysts between IVM media may appear only when the developmental stages are taken into account.

Serum osteoprotegerin and receptor activator of nuclear factor-kappaB ligand (RANKL) concentrations in allogeneic stem cell transplant-recipients: a role in bone loss?

PURPOSE

Osteoporosis is a long-term complication of allogeneic stem cell transplantation (SCT). Receptor activator of nuclear factor-kappaB ligand (RANKL) increases osteoclast activity, while osteoprotegerin (OPG) neutralizes RANKL. A deficiency of OPG or an excess of RANKL may contribute to post-SCT bone loss.

METHODS

Serum OPG and soluble RANKL (sRANKL) concentrations were determined in 30 patients who received calcium, vitamin D and sex steroids--with or without pamidronate--prior to SCT and 1, 3, 6, and 12 months post-SCT and compared to those in healthy controls.

RESULTS

Despite all treatments patients lost bone at the hip. At baseline, serum OPG was similar in patients and controls; in the two patient groups it increased by 26-27% at 6 months post-SCT (p=0.002-0.028) and over the control level (p=0.002). Serum sRANKL concentrations were also similar in patients and controls at baseline. In those patients receiving pamidronate sRANKL concentrations decreased by 42% (p=0.0007) at 3 months post-SCT. The findings on the effect of SCT on OPG and sRANKL serum levels were ascertained in 28 additional patients who did not receive pamidronate, at a median of 122 days after SCT. In this latter group, OPG but not sRANKL concentrations were clearly elevated (p<0.001) in comparison to healthy controls. In conclusion, the present study fails to support the view that an excess of sRANKL or a deficiency of OPG would have a substantial impact on bone loss in SCT-recipients.

CONCLUSION

Serum sRANKL concentrations may be modulated by bisphosphonates.

Recovery of bone mass and normalization of bone turnover in long-term survivors of allogeneic bone marrow transplantation

Osteoporotic fractures are potential long-term complications of bone marrow transplantation (BMT). We previously reported that bone mineral density (BMD) of patients undergoing allogeneic BMT decreased by 6% to 9% during the first 6 months after BMT and that bone turnover rate was still increased 1 year after BMT. BMT patients do not need lifelong immunosuppressive treatment, which should offer favorable circumstances for the recovery of BMD. Thus, 27 (14 women, 13 men) of 29 long-term survivors of our previous study were invited to a follow-up study at a median of 75 months after BMT. From 12 months after BMT the BMD of the lumbar spine had increased by 2.4% (P = 0.002). The respective changes in femoral sites were +4.1% in the femoral neck (P = 0.087), 4.0% in the trochanter (P = 0.095), +4.7% in Ward's triangle (P = 0.072) and +1.4% in the total hip (P = 0.23). The markers of bone formation, serum osteocalcin and type I procollagen aminoterminal propeptide (PINP) had returned to control levels, but out of the markers of bone resorption the mean level of serum type I carboxyterminal telopeptide (ICTP) was 41% higher (P = 0.0001) and that of urinary type I collagen N-terminal telopeptide/creatinine (NTx) 41% lower (P = 0.0002) in patients than in controls. The mean serum 25-hydroxyvitamin D [25(OH)D] was 33% lower in patients (P = 0.0002), most of whom had hypovitaminosis D [serum 25(OH)D < or = 37 nmol/l]. Except for two, males had serum testosterone level lower than before BMT and four men had hypogonadism. In conclusion, in long-term survivors of allogeneic BMT BMD recovers and bone turnover state normalizes as compared to the situation 1 year after BMT. More attention should be paid to the vitamin D status of all recipients and to possible hypogonadism of male patients.

Direct luteinizing hormone action triggers adrenocortical tumorigenesis in castrated mice transgenic for the murine inhibin alpha-subunit promoter/simian virus 40 T-antigen fusion gene

Transgenic (TG) mice, expressing the Simian Virus 40 T-antigen (Tag) under a 6-kb fragment of the murine inhibin alpha-subunit promoter (inh alpha p), develop gonadal tumors of granulosa/theca or Leydig cell origin. We showed previously that adrenocortical tumors develop if the TG mice are gonadectomized but never develop in intact animals. However, if functional gonadectomy was induced by GnRH antagonist treatment or by cross-breeding the TG mice into the hypogonadotropic hpg genetic background, neither gonadal nor adrenal tumors appeared. Since the most obvious difference between the gonadectomized and GnRH-antagonist-treated or Tag/hpg double mutant mice is the elevated gonadotropin secretion in the first group, we examined whether the adrenal tumorigenesis would be gonadotropin-dependent. Surprisingly, both the adrenal tumors and a cell line (C alpha 1) derived from one of them expressed highly functional LH receptors (LHR), as assessed by Northern hybridization, immunocytochemistry, ligand binding, and human CG (hCG)-stimulated cAMP and steroid production. No FSH receptor expression was found in the adrenal tumors by RT-PCR. hCG treatment of the C alpha 1 cells stimulated their proliferation, as measured by [3H]thymidine incorporation. This effect was related to hCG-stimulated steroidogenesis since progesterone, testosterone, and estradiol, at physiological concentrations, also stimulated the C alpha 1 cell proliferation. Different adrenocortical cells expressed initially LHR and Tag, whereas both were highly expressed in the tumor cells. In conclusion, the high level of functional LHR in the adrenal tumors indicates that this receptor can function as tumor promoter when ectopically expressed and stimulated by the ligand hormone.

Stable transfection of the rat follicle-stimulating hormone receptor complementary DNA into an immortalized murine Sertoli cell line

A plasmid expressing the rat FSH receptor (R) cDNA under the Simian virus (SV) 40 promoter/enhancer was stably transfected into a mouse Sertoli cell (SC) line (MSC-1) established from transgenic mice carrying a fusion gene of the human anti-Müllerian hormone (AMH) promoter sequences linked to the SV40 T-antigen gene (Peschon et al., 1992). The original cell line has numerous SC characteristics, but it was reported not to express the inhibin-alpha and follicle-stimulating hormone (FSH)R genes. The new FSHR expressing cell line possessed approximately 2000 per cell with equilibrium association constant (Ka) of 1.5 x 10(9) l/mol. In Northern blots, an FSHR mRNA species of 2.6 kb was found. The cells responded to recombinant human FSH (recFSH) and pertussis toxin (PT) with stimulated cAMP production. Moreover, PT enhanced the FSH-stimulated cAMP production in these cells, indicating the presence of a functional Gi protein. 12-O-tetradecanoylphorbol-13-acetate (TPA) suppressed the FSH-stimulated cAMP production of the cells, which effect was similar to that observed previously upon protein kinase C (PKC) activation in rat seminiferous tubules in vitro. Hence, the FSHR signalling, and its modulatory pathways, were intact in the FSHR expressing MSC-1 cell line. RT-PCR with inhibin-alpha specific oligonucleotide primers. followed by Southern hybridization, indicated that, unlike previously shown, the original and the FSHR expressing MSC-1 cells do express the inhibin alpha gene. FSH stimulation of the cells decreased their proliferation and, unexpectedly, the inhibin-alpha mRNA levels. The cells have functional features both from neonatal and mature SC. A feature of the former cells is the lack of FSH-stimulated up-regulation of inhibin-alpha expression; in fact FSH decreased this message. The antiproliferative, and apparently differentiating, effect of FSH on these cells resembled mature SC functions. Since adult SC do not proliferate in vitro, the new FSHR expressing and proliferating cell line provides a useful in vitro model for studying some facets of SC functions, though keeping in mind that these transformed cells do not behave identically with adult SC in vivo. The constitutive expression of FSHR in these cells allows the study of posttranscriptional events in the FSHR regulation.

Suppression of gonadotropins inhibits gonadal tumorigenesis in mice transgenic for the mouse inhibin alpha-subunit promoter/simian virus 40 T-antigen fusion gene

We have previously developed a transgenic (TG) mouse model expressing the Simian virus 40 T-antigen (Tag), driven by a 6-kb fragment of the mouse inhibin alpha-subunit promoter (inh-alpha). The mice develop metastasizing gonadal tumors, of granulosa/theca or Leydig cell origin, with 100% penetrance by the age of 5-8 months. In the present study, we examined whether the appearance and growth of the gonadal tumors are dependent on gonadotropins. Gonadotropin suppression was achieved either by treatment of 3-month-old mice for 2-3 months with a GnRH antagonist (Cetrorelix, SB-75), or by cross-breeding the TG mice to the genetic background of the gonadotropin-deficient hypogonadal mutant mouse (hpg). Gonadal tumor growth was clearly inhibited by SB-75 treatment in one of the TG mouse lines (IT6-M), as indicated by the absence of macroscopically visible tumors and by reduced gonadal weights. Despite the suppressed gonadotropin secretion and Tag expression, hyperplasia of testicular Leydig, and ovarian stromal cells persisted in some of the treated mice. In another TG mouse line (IT6-F), with more aggressive tumorigenesis, the SB-75 treatment only partially inhibited gonadal tumor growth. None of the hypogonadotropic TG mice, homozygous for the hpg mutation, developed gonadal tumors. Their gonadal histology was indistinguishable from that of the non-TG hpg mice, suggesting total inhibition of gonadal tumorigenesis in the absence of gonadotropin stimulation. Tag expression and Leydig cell hyperplasia were apparent already in the postnatal TG mice but absent in those TG mice homozygous for the hpg mutation. In conclusion, the present results indicate that the gonadal tumorigenesis in our TG mouse model starts in early age as hyperplasia in specific somatic cells. Both this, and the subsequent malignant tumor growth, are gonadotropin dependent. A sufficient level of Tag expression, a prerequisite for gonadal tumorigenesis, only occurs upon gonadotropin stimulation.

Characterization of paracellular and aqueous penetration routes in cornea, conjunctiva, and sclera

PURPOSE

To characterize quantitatively the paracellular permeation routes in rabbit cornea, conjunctiva, and sclera using polyethylene glycol (PEG) oligomers.

METHODS

Corneal, conjunctival, and scleral tissues from New Zealand white rabbits were tested individually in a modified two-chamber Ussing apparatus with the mixture of PEGs with mean molecular weights 200, 400, 600, and 1000 in glutathione bicarbonated Ringer's solution buffer on the donor side of the chamber. The samples and standards were analyzed with high-performance liquid chromatography-thermospray mass spectrometry method. The pore sizes and the pore densities of the corneal and conjunctival epithelia were calculated using an effusion-like approach.

RESULTS

The conjunctival and scleral tissues were 15 to 25 times more permeable than the cornea and the molecular size affected the conjunctival permeability less than that of the cornea. The palpebral and bulbar conjunctivas had equal permeabilities. The scleral permeability was approximately half of that in the conjunctiva and approximately 10 times more than in the cornea. The conjunctival epithelia had 2 times larger pores and 16 times higher pore density than the cornea. The total paracellular space in the conjunctiva was estimated to be 230 times greater than that in the cornea.

CONCLUSIONS

The conjunctival epithelium, due to its higher membrane permeability and larger absorptive and intercellular space surface areas, is the most viable route for ocular delivery of peptides and oligonucleotides.

Gonadectomy permits adrenocortical tumorigenesis in mice transgenic for the mouse inhibin alpha-subunit promoter/simian virus 40 T-antigen fusion gene: evidence for negative autoregulation of the inhibin alpha-subunit gene

We have developed a transgenic (TG) mouse model for gonadal tumorigenesis expressing the Simian virus 40 T-antigen (Tag) under the mouse inhibin alpha-subunit promoter. Gonadal tumors appear with 100% penetrance by the age of 5-8 months in the TG mice. When 1-month-old TG mice were gonadectomized, adrenal gland tumors were observed in each animal (12 females, 11 males) at the age of 6-8 months. No adrenal tumors were detected in gonadectomized non-TG mice (nine females, nine males) or in the intact TG mice (n > 100). The tumors appeared to originate from the X zone of the adrenal cortex. The TG mice with adrenocortical tumors had elevated serum levels of progesterone, estradiol, and immunoreactive inhibin (including dimeric forms), but corticosterone secretion was reduced. The lack of adrenal tumors in intact TG mice suggested that the tumorous gonads secrete factor(s) inhibiting adrenal tumorigenesis. As a candidate molecule, we studied the effects of inhibin, which was high in the serum of control females and TG females with ovarian tumors, as well as in TG males with testicular tumors. The DNA synthesis, as well as the levels of inhibin-alpha and Tag mRNA expression, were significantly reduced by recombinant human inhibin A in cell cultures derived from the adrenal tumors. In accordance, the expression level of inhibin-alpha mRNA in the normal adrenal gland was elevated 2 weeks after gonadectomy. These findings suggest that gonadal inhibin can down-regulate the expression of the inhibin alpha-subunit gene in the adrenal gland. When circulating inhibin is eliminated by gonadectomy, Tag expression and tumorigenesis are stimulated in the adrenal glands of the TG mice. The results demonstrate a novel mechanism of autoregulation in inhibin alpha-subunit gene expression.

Pituitary and ovarian expression of the endogenous follicle-stimulating hormone (FSH) subunit genes and an FSH beta-subunit promoter-driven herpes simplex virus thymidine kinase gene in transgenic mice; specific partial ablation of FSH-producing cells by antiherpes treatment

The ovarian expression of the endogenous follicle-stimulating hormone beta-subunit (FSH beta) and common alpha-subunit (C alpha) genes, and a herpes simplex virus thymidine kinase (tk) transgene, driven by a 2.3 kb bovine FSH beta promoter, was studied in normal and transgenic (tg) mice, tk functions not only as a neutral reporter that enables the study of the promoter function but also as an exogenously inducible toxigene. Reverse transcription-PCR followed by Southern blot hybridization with a nested probe was used to show the expression of the gene at the mRNA level. Common alpha-subunit mRNA was detected in the pituitary gland and ovaries of normal adult mice. We have previously detected endogenous FSH beta and tg tk mRNAs in the mouse pituitary, testis and ovary. In this study, the cellular localization of the corresponding proteins was visualized by immunocytochemistry. In normal mouse ovaries a positive reaction with FSH beta and C alpha antisera was seen in some of the corpora lutea and most prominently in the interstitial cells. A positive reaction with the tk antiserum was seen in the same cell types of tg mouse ovaries, but not in those of non-tg mice. Cell-ablation-inducing treatment (gancyclovir, 20 mg/kg per day, for 14 days) of tg female mice reduced pituitary FSH concentrations by 52% (P < 0.05) but did not affect pituitary LH or plasma gonadotropins compared with non-tg females treated in the same way. A longer period of cell ablation induction (acyclovir 400 mg/kg per day, for 21 days) reduced not only pituitary but also plasma FSH concentrations (55 and 57% respectively; P < 0.05) without affecting LH. This treatment also reduced ovarian weight by 38% (P < 0.01). In conclusion, our results show first that the endogenous FSH beta and C alpha proteins are produced in the mouse ovary. Hence, endogenously synthesized FSH or its subunits may have a role in the paracrine regulation of ovarian function. Secondly, the FSH beta promoter directs the expression of tg tk in the pituitary gonadotrope cells, as shown by specific but partial ablation of FSH-producing cells after induction by gancyclovir and acyclovir. In the ovary, tk protein was localized to the same compartments as the endogenous gonadotropin subunit proteins. This further confirms our finding of ovarian expression of the FSH subunit genes.

The mouse inhibin alpha-subunit promoter directs SV40 T-antigen to Leydig cells in transgenic mice

Testicular tumorigenesis was observed in transgenic mice expressing the 6-kb mouse inhibin alpha-subunit promoter/Simian virus 40 T-antigen (SV40 Tag) fusion gene. The tumors were confined to Leydig cells using immunohistochemistry with anti-Tag antibody, specific binding of biotinylated hCG and histochemistry for 3 beta-hydroxysteroid dehydrogenase. Leydig cell hyperplasia and presence of Tag protein in the testicular interstitial tissue were already evident at 5 and 6.5 days of age, respectively. An immortalized cell line, BLT-1, was established from one testicular tumor. These cells expressed the LH receptor and P450scc mRNAs, and displayed LH-responsive cAMP and progesterone production, and low testosterone production. The cells also specifically bound 125I-labeled recombinant human LH with high affinity (36000 binding sites/cell), and the binding was regulated by 8Br-cAMP and hCG. This gonadal tumor model is valuable for further studies on endocrine functions of Leydig cells and their tumorigenesis in vivo and in vitro.

A 252 bp upstream region of the rat spermatocyte-specific hst70 gene is sufficient to promote expression of the hst70-CAT hybrid gene in testis and brain of transgenic mice

The rat hst70 gene belongs to a heat shock hsp70 multigene family and its expression has been detected so far solely in spermatocytes. To investigate the cis-elements responsible for testis-specific expression of the hst70 gene we produced several lines of transgenic mice carrying fragments of the 5'-flanking regions of the hst70 gene fused to the chloramphenicol acetyltransferase (CAT) reporter gene. Hybrid genes of series B were constructed such that, besides the 780 bp, 343 bp and 163 bp 5'-flanking region these plasmids contained no other sequences of the hst70 gene. In hybrid genes of series D the CAT gene was ligated to 343 bp and 252 bp 5'-flanking regions together with the 57 bp of the 5'-end nontranslated (leader) sequences of the hst70 gene. We found that in 780/B, 343/B, 343/D and 252/D adult mice the transgene was specifically and highly expressed in testes. In developing testes the high CAT activity appeared in transgenic mice aged 3 weeks and older. None of the three 163/B transgenic lines exhibited CAT activity in any tissue analyzed. In all CAT expressing lines a weak but significant CAT activity (up to 5% of that in testis) was detected also in the brain. RNase protection assay confirmed that the endogenous hst70 gene transcripts are present in testis as well as in brain of nontransgenic rats and mice. Our data show that the cis-regulatory sequences responsible for testis-specific and developmentally regulated expression of the hst70 gene are localized within the 252 bp region 5' to the gene and neither the 5'-end nor 3'-end nontranslated sequences of the gene are important for this specificity.

Gonadal tumorigenesis in transgenic mice bearing the mouse inhibin alpha-subunit promoter/simian virus T-antigen fusion gene: characterization of ovarian tumors and establishment of gonadotropin-responsive granulosa cell lines

To establish in vivo gonadal tumor models and permanent lines of gonadal somatic cells we produced transgenic (TG) mice expressing the Simian virus (SV) 40 T-antigens (T-ag), driven by 6 or 2.1 kilobase fragments of the mouse inhibin alpha-subunit promoter. Hitherto, altogether 44 TG mice, one of which carried the shorter transgene, have produced gonadal tumors. Two founder females expressing the longer transgene, KK1 and KK3, and three established TG mouse lines were studied in detail. Penetrance of the phenotype in IT6-M and IT6-F mouse lines was 100% (tumors/TG: IT6-M 22/22, IT6-F 14/14). The T-ag mRNA was strongly expressed in the gonads, adrenal glands, pituitary, and brain. The KK-1 and KK-3 ovarian tumor cells immunostained with anti-SV40 large-T antibody. The KK-1 cells possessed high-affinity LH receptors [equilibrium association constant (Ka = 7.8 x 10(10) liters/mol] and responded to human CG by elevated cAMP and progesterone production. Also FSH slightly stimulated their cAMP and estradiol production (P < 0.01). These cells expressed cytochrome P450arom and inhibin alpha mRNA, but not cytochrome P450c17 alpha. In conclusion, the KK-1 cells are immortalized luteinizing granulosa cells expressing endogenous gonadotropin receptors, steroidogenic enzymes, and inhibin alpha. These cells will be useful in studies on the molecular aspects of granulosa cell function. The present study indicates that the 6-kilobase fragment of the inhibin alpha promoter described in this article contains the elements directing tissue-specific expression in vivo and is useful for targeted expression of other genes in the gonads.

Induced ablation of gonadotropins in transgenic mice expressing herpes simplex virus thymidine kinase under the FSH beta-subunit promoter

Suppression of gonadotropins was induced by gancyclovir or acyclovir treatment in transgenic mice carrying 2.3 kb of bovine follicle-stimulating hormone beta (FSH beta) promoter fused to Herpes simplex virus thymidine kinase (tk) coding sequence. Transgenic tk and endogenous FSH beta were immunohistochemically co-localized in the same pituitary cells. In adult castrated transgenic males, gancyclovir treatment reduced plasma FSH (30%, P < 0.001). In intact juvenile gancyclovir treated mice, the reduction of pituitary FSH, and in males also of plasma FSH, was greater (50-70%, P < 0.05-0.01). A concomitant suppression of luteinizing hormone (LH) (50%, P < 0.01) was observed in female pups. The most pronounced reduction of gonadotropins was observed in newborn transgenic pups treated in utero with acyclovir. Both males and females had significantly lower pituitary levels of FSH (75-55%), LH (80-90%) or both (P < 0.05-0.01). Less pronounced decreases (30-40%, P < 0.01) were observed in plasma FSH. No apparent defects were seen in the testes of the transgenic, acyclovir treated, newborn pups. This mouse model is applied to study the dynamics of the gonadotropes and the role of gonadotropins in the maturation of the reproductive functions.