Human chorionic gonadotropin inhibits Kaposi's sarcoma associated angiogenesis, matrix metalloprotease activity, and tumor growth

Lifestyle factors associated with sex differences in Kaposi sarcoma incidence among adult black South Africans: A case-control study

Kaposi Sarcoma (KS) is endemic in several countries in Southern and Eastern Africa, relatively rare worldwide but a leading cancer among people living with HIV. KS has always been more common in adult males than females. We assessed the prevalence of known cancer modifying factors (parity, hormonal contraceptive use in females, sex-partners, smoking and alcohol consumption in both sexes), and their relationship to KS, and whether any of these could account for the unequal KS sex ratios. We calculated logistic regression case-control adjusted odds ratios (OR_adj), and 95% confidence intervals (95%CI), between KS and each of the modifying factors, using appropriate comparison controls. Controls were cancer types that had no known relationship to exposures of interest (infection or alcohol or smoking or contraceptive use). The majority of the 1275 KS cases were HIV positive (97%), vs. 15.7% in 10,309 controls. The risk of KS among those with HIV was high in males (OR_adj=116.70;95%CI=71.35-190.88) and females (OR_adj=93.91;95%CI=54.22-162.40). Among controls, the prevalence of smoking and alcohol consumption was five and three times higher in males vs. females. We found a positive association between KS and heavy vs. non-drinking (OR_adj=1.31;95%CI=1.03-1.67), and in current heavy vs. never smokers (OR_adj=1.82;95%CI=1.07-3.10). These associations remained positive for alcohol consumption (but with wider CIs) after stratification by sex, and restriction to HIV positive participants. We found no evidence of interactions of smoking and alcohol by sex. Smoking and alcohol consumption may provide a possible explanation for the KS sex differences, given both exposures are more common in men, but confounding and bias cannot be fully ruled out. The role smoking and alcohol play in relation to viral loads of HIV/KSHV, differences in immunological responses or other genetic differences between males and females warrant further studies.

[HIV-related malignancies: state of art]

HIV infection is related to an increased risk of cancer compared with general population, both AIDS-defining cancers (Kaposi's sarcoma, non Hodgkin's lymphoma, invasive cervical cancer) and non-AIDS-defining cancers. Although the advent of the highly active antiretroviral therapy era has decreased the Kaposi's sarcoma and non-Hodgkin's lymphoma incidences, non-AIDS-defining malignancies, such as lung cancer, hepatocarcinoma, anal cancer and skin cancers, remain a major cause of morbidity and death in the HIV-infected population. The clinical presentation is often different between the infected and non-infected populations, often with a more advanced stage at diagnosis, a more aggressive pathology, and associated morbidities like immunosuppression, leading to poorer outcomes. Numerous studies have focused on HIV-related malignancies' treatment, however specific guidelines are still missing. Practitioners have to be careful with interactions between antiretroviral and antineoplastic drugs, particularly through the cytochrome P 450. Because of this, a national multidisciplinary approach, "Cancer and HIV, " was started in 2013 thanks to the National Institute of Cancer (INCa). The aim of this review is to present a scientific update about AIDS-and non-AIDS-defining malignancies, both in their clinical aspects and regarding their specific therapeutic management.

Luteinizing hormone receptor deficiency increases the susceptibility to alkylating agent-induced lymphomagenesis in mice

Previous studies have revealed a close link between luteinizing hormone (LH)/human chorionic gonadotropin (hCG) signaling and oncogenesis in gonadal and nongonadal tissues. To investigate whether genetic ablation of LH receptor (Lhr) affects the animal's oncogenic susceptibility, adult female wild-type (wt), heterozygous, and homozygous Lhr knockout (LhrKO) mice were intraperitoneally injected with an alkylating agent, N-methyl-N-nitrosourea (MNU, 50 mg/kg of body weight). The mice were sacrificed when they were short of breath or 10 months after the injection. The results showed that MNU induced non-Hodgkin's thymic and lymphonodus lymphomas in 70.6% and 100% of heterozygous and homozygous animals, respectively, compared with 35.7% in wt siblings. The tumor development was rapid; they were more aggressive and metastasized to the spleen, liver, and kidney in Lhr-deficient mice compared to wt siblings. All tumors were immunostained-positive for a T-cell specific marker, CD3, but not for a B-cell marker, CD22, suggesting that all the lymphomas arose from T-cells, which are known to be LH/hCG receptor-positive. There was no rearrangement of the Lhr gene locus or differences in thymic cell proliferation among the genotypes. However, apoptosis was lower in the Lhr-deficient thymuses. The thymic Bcl-2 levels were elevated and caspase-3 activation was reduced in Lhr heterozygous and homozygous animals. In conclusion, MNU induced a higher incidence and an earlier onset of aggressive lymphomas in LhrKO animals, which may be associated with a reduction in apoptosis of thymocytes.

Accelerated wound healing mediated by activation of Toll-like receptor 9

Wound healing is mediated through complex interactions between circulating immune cells and local epithelial and endothelial cells. Elements of the innate immune system are triggered when Toll-like receptors (TLR) are stimulated by their cognate ligands, and previous studies suggest that such interactions can accelerate wound healing. This work examines the effect of treating excisional skin biopsies with immunostimulatory CpG oligodeoxynucleotides (ODN) that trigger via TLR9. Results indicate that CpG (but not control) ODN accelerate wound closure and reduce the total wound area exposed over time by >40% (p<0.01). TLR9 knockout mice, a strain unresponsive to the immunomodulatory effects of CpG stimulation, are unresponsive to ODN treatment and exhibit a general delay in healing when compared with wild-type mice. CpG ODN administration promoted the influx of macrophages to the wound site and increased the production of vascular endothelial growth factor, expediting neovascularization of the wound bed (p<0.01 for both parameters). Stimulation via TLR9 thus represents a novel strategy to accelerate wound healing.

Functional genomics of endothelial cells treated with anti-angiogenic or angiopreventive drugs

Angiogenesis is a highly regulated physiological process that has been studied in considerable detail given its importance in several chronic pathologies. Many endogenous factors and hormones intervene in the regulation of angiogensis and classical as well as targeted drugs have been developed for its control. Angiogenesis inhibition has come off the bench and entered into clinical application for cancer therapy, particularly for metastatic disease. While the clinical benefit is currently in terms of months, preclinical data suggest that novel drugs and drug combinations could lead to substantial improvement. The many targets of endogenous angiogenesis inhibitors reflect the complexity of the process; in contrast, current clinical therapies mainly target the vascular endothelial growth factor system. Cancer chemopreventive compounds can retard tumor insurgence and delay or prevent metastasis and many of these molecules hinder angiogenesis, a mechanism that we termed angioprevention. Angiopreventive drugs appear to prevalently act through the inhibition of the pro-inflammatory and anti-apoptotic player NFkappaB, thus contrasting inflammation dependent angiogenesis. Relatively little is known concerning the effects of these angiogenesis inhibitors on gene expression of endothelial cells, the main target of many of these molecules. Here we provide an exhaustive list of anti-angiogenic molecules, and summarize their effects, where known, on the transcriptome and functional genomics of endothelial cells. The regulation of specific genes can be crucial to preventive or therapeutic intervention. Further, novel targets might help to circumvent resistance to anti-angiogenic therapy. The studies we review are relevant not only to cancer but also to other chronic degenerative diseases involving endothelial cells, such as cardiovascular disorders, diabetes, rheumatoid arthritis and retinopaties, as well as vessel aging.

Human chorionic gonadotropin prevents Sjögren's syndrome-like exocrinopathy in mice

OBJECTIVE

Results of recent studies suggest that human chorionic gonadotropin (HCG), a placental glycoprotein hormone required for the maintenance of pregnancy, may have immunomodulatory properties. Primary Sjögren's syndrome (SS), a chronic autoimmune disorder of unknown etiology, affects multiple exocrine glands including the salivary and lacrimal glands. The purpose of the present study was to determine whether HCG could prevent the development of salivary gland exocrinopathy in NOD mice, an experimental model of Sjögren's-like syndrome.

METHODS

Female NOD mice were treated with HCG from 6 weeks of age to 12 weeks of age. At 14 weeks, tissue samples were evaluated for inflammatory lesions and cytokine messenger RNA by real-time polymerase chain reaction. At 18 weeks, the salivary flow rate was measured.

RESULTS

Treatment with HCG resulted in a significant decrease in lymphocyte infiltration and parenchymal cell damage in the submandibular salivary glands. Messenger RNA levels of interferon-gamma, tumor necrosis factor alpha, interleukin-1beta, and interleukin-10, as well as inducible nitric oxide synthase and matrix metalloproteinase 9, were significantly decreased. Function studies revealed a marked increase in the salivary flow rate in HCG-treated mice compared with that in phosphate buffered saline-treated mice.

CONCLUSION

In NOD mice, HCG acts as an immune modulator and prevents the development of salivary gland exocrinopathy. These findings suggest that HCG, a naturally occurring reproductive hormone, may be useful in the treatment of Sjögren's syndrome and other human autoimmune diseases.

Matrix metalloproteinases in the progression and regression of Kaposi's sarcoma

BACKGROUND

Matrix metalloproteinases (MMPs) are associated with Kaposi's sarcoma (KS) tumorigenesis. To date, only a few MMPs have been studied in KS lesions. Their role in KS regression has not been investigated. The aim of this study was to evaluate the expression of multiple MMPs in developing and pharmacologically regressed KS lesions.

METHODS

Nine samples of acquired immune deficiency syndrome (AIDS)-related and classic cutaneous KS lesions at various histological stages were studied. Regressing KS lesions from three patients treated with systemic therapy were procured after one and two cycles of chemotherapy. Tissue sections from all specimens were immunostained using monoclonal antibodies to MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, MMP-13, and MMP-14.

RESULTS

KS lesional cells were immunoreactive for all MMPs, except MMP-14. Admixed inflammatory cells were immunoreactive for MMP-1, MMP-2, MMP-7, MMP-9, and MMP-13. The MMP immunoprofile in residual KS lesional cells was unaltered in regressed lesions. Increased extracellular matrix (ECM) and macrophage immunoreactivity for MMPs was identified in regressed specimens.

CONCLUSIONS

These data show that developing KS lesional cells express collagenases (MMP-1, MMP-13), gelatinases (MMP-2, MMP-9), stromelysin-1 (MMP-3), and matrilysin (MMP-7) but not the membrane-type MMP-14. This MMP expression profile is retained by residual KS cells and also expressed by infiltrating macrophages in regressed KS lesions. Pantanowitz L, Dezube BJ, Hernandez-Barrantes S, Tahan SR, Dabbous MK. Matrix metalloproteinases in the progression and regression of Kaposi's sarcoma.

Pregnancy and human herpesvirus 8 reactivation in human immunodeficiency virus type 1-infected women

To investigate the impact of pregnancy on human herpesvirus 8 (HHV-8) reactivation in human immunodeficiency virus type 1 (HIV-1)-infected women, the HHV-8 DNA presence and load were analyzed in peripheral blood mononuclear cells (PBMCs) and cervicovaginal secretions (CVSs) from 15 pregnant women coinfected with HIV-1 and HHV-8. HHV-8 detection was analyzed in relation to anti-HHV-8 antibodies and HIV-1-related parameters. Nucleotide sequence analysis of an ORFK1 hypervariable region of the HHV-8 strains was performed. HHV-8 was detected in maternal PBMCs (5/15 women) from the second trimester and in CVSs (5/15 women) mainly from the third trimester. The HHV-8 load significantly increased late in pregnancy in both maternal compartments and was associated with a significant increase in HIV-1 shedding in the genital tract. Antilytic antibodies were significantly more common in HHV-8 DNA-positive women. An elevated HHV-8 load was found in the PBMCs of an infant born to a mother with large amounts of HHV-8 in both compartments at delivery. Different ORFK1 subtypes were found in maternal samples, whereas the same subtype was identified in the mother-child pair. These data suggest that pregnancy may induce HHV-8 replication in HIV-1-infected women. An augmented HHV-8 load may, in turn, influence mother-to-child transmission, since one of the HIV-1-infected mothers with HHV-8 reactivation transmitted her ORFK1 subtype to the infant, who showed a high level of HHV-8 viremia indicative of a primary infection. This finding documents for the first time the perinatal transmission of a specific HHV-8 subtype. Vertical transmission may thus play a role in HHV-8 spread also in areas of subendemicity among HIV-1-infected women.

Inhibition of angiogenesis in vivo and growth of Kaposi's sarcoma xenograft tumors by the anti-malarial artesunate

Artesunate (ART) is a semi-synthetic derivative of the sesquiterpene artemisinin used for the second line therapy of malaria infections with Plasmodium falciparum. ART also inhibits growth of many transformed cell lines. In the present investigation, we show that ART inhibited the growth of normal human umbilical endothelial cells and of KS-IMM cells that we have established from a Kaposi's sarcoma lesion obtained from a renal transplant patient. The growth inhibitory activity correlated with the induction of apoptosis in KS-IMM cells. Apoptosis was not observed in normal endothelial cells, which, however, showed drastically increased cell doubling times upon ART treatment. ART strongly reduced angiogenesis in vivo in terms of vascularization of Matrigel plugs injected subcutaneously into syngenic mice. We conclude that ART represents a promising candidate drug for the treatment of the highly angiogenic Kaposi's sarcoma. As a low-cost drug, it might be of particular interest for areas of Kaposi's sarcoma endemics. ART could be useful for the prevention of tumor angiogenesis.