Emerging treatments for epidemic (AIDS-related) Kaposi's sarcoma

Skin Cancer and Immunosuppression

Immunosuppressed patients are at significantly increased risk of developing cutaneous malignancies. These malignancies are often more aggressive compared with the general population and require multidisciplinary care. This article highlights the incidence and risk factors of cutaneous malignancies in this cohort. The treatment and prevention strategies are discussed. There continues to be a need for evidence-driven guidelines regarding the management of skin cancers in these patients.

Massive vulval Kaposi's sarcoma in pregnancy: case report

Introduction

The complications of HIV/AIDS can produce grossly abnormal pathology. In low-resourced settings, women can present late with huge lesions. Massive vulval pathology copresenting in pregnancy produces difficulties in managing the patients and may lead to poor maternal or fetal outcomes.

Case report

A 27-year-old P1 G2 (second pregnancy one live birth) patient presented at 30 weeks gestation with a massive vulval lesion. She was HIV seropositive and taking anti-retroviral therapy. She was anemic with a hemoglobin level of 5.9 and was transfused 4.0 of packed cells. She underwent examination under anesthesia and vulval biopsy. She went into preterm labor and was delivered by cesarean section. Unfortunately, the baby had died while receiving corticosteroid therapy. The histopathological report confirmed a Kaposi’s sarcoma, and she was referred to oncologists for chemotherapy.

Conclusion

Kaposi’s sarcoma can occur in pregnancy in both seropositive and seronegative patients. Kaposi’s sarcoma causes significant fetal and maternal health complications.

Induction of paclitaxel resistance by the Kaposi's sarcoma-associated herpesvirus latent protein LANA2

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causal agent of both KS and primary effusion lymphoma (PEL). Although treatment with paclitaxel has significant antitumor activity in KS, drug resistance represents a major obstacle for improving the overall response and survival of PEL patients. The transcriptional pattern of KSHV is cell/tissue specific, as revealed by the fact that the viral latent protein LANA2 is detected exclusively in B cells. This paper focuses on the mechanism of paclitaxel resistance observed in PEL cells. Here we show that LANA2 protein modulates microtubule dynamics through its direct binding to polymerized microtubules, preventing microtubule stabilization induced by paclitaxel. This is the first demonstration of paclitaxel resistance induced by a viral protein and suggests a link between the expression of LANA2 and the resistance of PEL cells to paclitaxel.

Use of liposomal anthracyclines in Kaposi’s sarcoma

Conventional chemotherapy regimens for the treatment of advanced Kaposi's sarcoma (KS) show limited efficacy and considerable toxicity. Liposomal anthracyclines with potential utility in KS include pegylated liposomal doxorubicin (Doxil/Caelyx [PLD]), daunorubicin citrate liposome (DaunoXome [DNX]), and nonpegylated liposomal doxorubicin (Myocet [NPLD]). Preclinical data showed that pegylated liposomes accumulate preferentially in highly vascularized KS lesions. In randomized clinical trials, PLD induced higher response rates than did the conventional combination chemotherapy regimens, bleomycin + vincristine (BV) and BV + conventional doxorubicin (ABV); DNX produced a response rate comparable to that of ABV. NPLD has not been compared with conventional chemotherapy for KS. PLD and DNX were associated with less toxicity compared with BV or ABV, including less alopecia and fewer gastrointestinal and neurologic side effects. Grade 3/4 myelosuppression was common with both PLD and DNX; stomatitis and infusion reactions occurred with PLD treatment, but hand-foot syndrome was relatively infrequent in the dose schedules used for KS. Health-related quality of life was improved in several domains in patients treated with PLD or DNX compared with ABV.

Staurosporine-induced G2/M arrest in primary effusion lymphoma BCBL-1 cells

Staurosporine, an inhibitor of protein kinase C, is a potential antitumor drug and its derivatives are used as anticancer drugs in clinical trials. Human herpesvirus 8 (HHV-8) is implicated in all forms of Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD), indicating it to be a DNA tumor virus. It is difficult to culture cell lines derived from KS patients; we therefore used a cell line derived from PEL (BCBL-1) to investigate whether staurosporine affects the HHV-8-related tumors. Our results show that staurosporine treatment reduces the cell viability of BCBL-1 cells and causes cell cycle arrest in the G2/M phase. The G2/M arrest was associated with the decrease in the expression of Cdc2 and cyclin B. Furthermore, the induction of the HHV-8 lytic cycle was not observed under the staurosporine treatment.

Gender differences and sex-specific manifestations associated with human immunodeficiency virus infection in women

The rapidly growing rates of human immunodeficiency virus (HIV) infection among women has prompted many challenging issues related to the management and consequences of HIV and its complications in this population. This paper reviews the current evidence with regard to various aspects of HIV infection in women. Special emphasis is placed on gender-differences as well as sex-specific manifestation of this disease, including epidemiology, viral load determination and disease progression, related morbidity, and anti-retroviral therapy. It is concluded that current advances in the understanding of HIV infection among women may lead to further refinement and optimization efforts in the management of HIV-infected women.

Acquired immunodeficiency syndrome-related Kaposi's sarcoma regression after highly active antiretroviral therapy: biologic correlates of clinical outcome

BACKGROUND

Kaposi's sarcoma (KS) is the most common cancer seen in subjects with acquired immunodeficiency syndrome (AIDS). KS etiology and pathogenesis are still ill defined, and no definite improvement in survival has been obtained with current chemotherapeutic regimens. This open prospective study was aimed at evaluating the clinical response of AIDS-related KS to highly active antiretroviral therapy (HAART), a combination of protease and reverse transcriptase inhibitors, as well as the relationship between clinical response, human immunodeficiency virus type 1 (HIV-1) burden, and antibody titer against human herpesvirus 8 (HHV8) proteins.

PATIENTS AND METHODS

Fourteen KS patients were studied; 12 were in the poor-risk group. At given intervals, the patients underwent clinical examination, and their CD4(+) cell counts, plasma HIV-1 RNA levels, and antibody titers to lytic-phase ORF65 and latent-phase HHV8 proteins were determined.

RESULTS

When last seen, the overall clinical response rate was 86% (median follow-up, 22 months); 10 complete and two partial responses were achieved, and two patients showed disease progression. All patients with complete or partial response showed a consistent decrease in HIV-1 RNA levels, with a corresponding increase in CD4(+) cell counts; HIV-1 RNA levels in the two progressors remained persistently high, despite a change in HAART. HHV8 ORF65 antibody titers were generally higher in patients with extensive skin or mucosal/visceral involvement versus patients with limited disease; no differences in latent-phase HHV8 antibody titers were observed in relation to tumor burden.

CONCLUSION

The findings indicate that antiretroviral therapy with protease inhibitors is effective for AIDS-related KS; the clinical response was correlated with a decrease in plasma HIV-1 RNA levels and an increase in CD4(+) lymphocytes, whereas antibody levels to the lytic-phase HHV8 protein were influenced by the extent of tumor involvement.

Suppression of metastatic hemangiosarcoma by a parvovirus MVMp vector transducing the IP-10 chemokine into immunocompetent mice

We have previously shown that the growth of human tumor xenografts in immunodeficient mice can be efficiently suppressed upon infection with the autonomous parvovirus H-1 or with cytokine-transducing derivatives thereof. To further evaluate the benefits of implementing parvoviruses in cancer gene therapy, we have created a new recombinant vector, MVMp/IP-10, transducing the immunoactive, antiangiogenic chemokine IP-10, and used this virus to treat syngeneic tumors grown in immunocompetent mice. Intratumoral/intraperitoneal administration of only 3 x 10(7) replication units of MVMp/IP-10 per animal strongly inhibited the progression of established H5V cell-induced vascular tumors, a highly malignant mouse model for human cavernous hemangioma and Kaposi's sarcoma. Retardation of recurrent tumor growth and suppression of life-threatening metastatic dissemination to internal organs were accompanied by a striking delay in hemangioma-associated mortality. Parental MVMp did not have a significant effect under these conditions up to the dose of 10(10) infectious units/animal, but had strong antihemangiosarcoma activity when used to infect H5V cells ex vivo prior to implantation. In all cases, virus therapy was very well tolerated. Virus-induced suppression of hemangiosarcoma was dependent on host T cells and associated with intratumoral persistence of IFN gamma-expressing cytotoxic lymphocytes, and led to the reduced expression of hepatic plasminogen activator inhibitor-1 (PAI-1), a metastasis-linked marker. This proof of principle study demonstrates that MVMp/IP-10 can aid the treatment of vascular tumors and that autonomous parvovirus-based vectors can be considered potent tools for cancer gene therapy purposes.

Docetaxel versus paclitaxel for antiangiogenesis

Cytoskeleton-toxic chemotherapeuticals, such as vinblastine and paclitaxel, display antiangiogenic activity. This study was designed to compare paclitaxel to its analog docetaxel and assess their doses still antiangiogenic in vitro and in vivo. Human endothelial cell functions involved in angiogenesis, namely proliferation, chemotaxis, morphogenesis, and secretion of matrix metalloproteinase-2 (MMP-2), MMP-9, and urokinase-type plasminogen activator (uPA) were studied in vitro upon exposure to docetaxel and paclitaxel, whereas their effect on angiogenesis was studied in vivo by using the chick embryo chorioallantoic membrane (CAM) model. Proliferation of mouse embryo fibroblasts and human Kaposi's sarcoma, breast and endometrial carcinoma, and lymphoid tumor cells was also studied. In vitro, 0.5, 0.75, and 1 nM docetaxel and 2, 3, and 4 nM paclitaxel, i.e., non-cytotoxic doses, impacted all endothelial cell functions, but not protease secretion, in a dose-dependent fashion, whereas they did not affect the proliferation of other cells, except those of Kaposi's sarcoma. No apoptosis was induced by 0.5 nM docetaxel and 2 nM paclitaxel, and moderate apoptosis was induced by 1 nM docetaxel and 4 nM paclitaxel. The antiangiogenic effect rapidly disappeared on drug suspension and was accompanied ultrastructurally by thin lesions of cytoskeleton in the form of slight and equally reversible depolymerization and accumulation of microfilaments. Massive endothelial cell apoptosis with evident cytotoxicity and irreversibility were associated with 2 nM docetaxel and 5 nM paclitaxel, although these higher doses were ineffective on other cells except Kaposi's sarcoma cells. In vivo, 1, 2, and 3 nM docetaxel and 4, 8, and 12 nM paclitaxel displayed a dose-dependent antiangiogenic activity. We suggest that very low docetaxel and paclitaxel doses selectively cause organic and functional damage of endothelial cells and that docetaxel is four times stronger. Their antiangiogenic activity could be applied to treat Kaposi's sarcoma and cancers.

Angiogenesis and antiangiogenic approaches to sarcomas

Established chemotherapy regimens for advanced or metastatic sarcoma generally have low response rates and substantial toxicity, and resistance often arises quickly, making sarcoma an ideal target for alternative treatment approaches. Antiangiogenic therapies have a number of potential advantages including decreased resistance, fewer side effects, and a broad spectrum of activity. This paper reviews the evidence supporting the use of antiangiogenic therapies for adult soft tissue sarcomas. Human sarcomas express a number of proangiogenic factors that may represent therapeutic targets, with vascular endothelial growth factor being the best characterized, and inhibitors of angiogenesis have antitumor activity in animal models of human sarcomas. Clinical trials are in early stages, although promising results have already been seen. In the future, improved drugs, refined molecular profiling of tumors, and new ways of combining antiangiogenic agents with cytotoxic agents may lead to more effective and tolerable therapies for sarcomas.

A case series of acquired immunodeficiency syndrome patients with initial neoplastic diagnoses of intraoral Kaposi's sarcoma

BACKGROUND

Oral Kaposi's sarcoma (KS) may represent the initial clinical manifestation of immunosuppression in human immunodeficiency virus disease. This article reviews the treatment provided to these patients and the outcome of the disease and provides the opportunity to assess the impact of improvements in the medical therapy of acquired immunodeficiency syndrome on disease outcome.

METHODS

A tumor registry was examined to identify patients in whom oral KS was the first neoplastic diagnosis.

RESULTS AND CONCLUSIONS

Thirty-seven cases of oral KS representing 1.9% of all cases of KS were identified as the first malignant diagnosis in patients with acquired immunodeficiency syndrome. Patients with oral KS have limited survival; the cause of death is either infection or malignancy. In our study, the palate was the most common site of primary involvement in the oral cavity. Recently diagnosed patients remained alive longer than those diagnosed earlier, and the patients with the most recently diagnosed cases were alive at the completion of the study, suggesting that medical management of human immunodeficiency virus has improved with new therapies.

The role of vascular endothelial growth factor (VEGF) in AIDS-related Kaposi's sarcoma

Kaposi's sarcoma (KS) is the most common neoplasm associated with human immunodeficiency virus-1 (HIV-1) infection. KS involves the skin and mucous membranes as well as other organs and can lead to tumor-associated edema and ulcerations. Despite therapy with highly active antiviral agents, most patients with HIV-1-related KS eventually develop disseminated disease. In the treatment of KS, a strong rationale exists for the use of agents that inhibit vascular endothelial growth factor (VEGF). Angiogenesis appears to be an important feature of this disease, and recent experimental studies have demonstrated the role of VEGF and its receptors in the pathogenesis of KS. Thus, therapeutic agents that target the VEGF pathway may be an effective strategy in reducing the tumor growth and edema associated with KS. Phase I study results with SU5416, a synthetic low molecular-weight inhibitor of the VEGF-Flk-1/KDR receptor tyrosine kinase, demonstrate that this agent is well tolerated. Preliminary results show that in a majority of patients with autoimmune deficiency syndrome (AIDS)-related disease, SU5416 clearly has biological activity (it flattens, shrinks, or dissolves lesions and reduces or resolves edema) or stabilizes the disease. Angiogenesis inhibition with SU5416 is a promising therapeutic approach in treating patients with KS, and further clinical evaluation is currently under way.

Target molecules for anti-angiogenic therapy: from basic research to clinical trials

There is growing evidence that anti-angiogenic drugs will improve future therapies of diseases like cancer, rheumatoid arthritis and ocular neovascularisation. However, it is still uncertain which kind of substance, out of the large number of angiogenesis inhibitors, will prove to be a suitable agent to treat these human diseases. There are currently more than 30 angiogenesis inhibitors in clinical trials and a multitude of promising new candidates are under investigation in vitro and in animal models. Important therapeutic strategies are: suppression of activity of the major angiogenic regulators like vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF); inhibition of function of alphav-integrins and matrix metalloproteinases (MMPs); the exploitation of endogenous anti-angiogenic molecules like angiostatin, endostatin or thrombospondin. Given the wide spectrum of diseases which could be treated by anti-angiogenic compounds, it is important for today's clinicians to understand their essential mode of action at a cellular and molecular level. Here we give an in-depth overview of the basic pathophysiological mechanisms underlying the different anti-angiogenic approaches used to date based on the most recent fundamental and clinical research data. The angiogenesis inhibitors in clinical trials are presented and promising future drug candidates are discussed.

Regression of AIDS-related Kaposi's sarcoma following antiretroviral therapy with protease inhibitors: biological correlates of clinical outcome

The clinical response of AIDS-related Kaposi's sarcoma (KS) to highly active antiretroviral therapy (HAART), a combination of human immunodeficiency virus type 1 (HIV-1) protease and reverse transcriptase inhibitors, was studied in 11 patients, all but one with progressive KS. CD4+ cell counts, plasma HIV-1 RNA levels, and antibody titres to lytic ORF65 and latency-associated human herpes virus type 8 (HHV-8) proteins were determined in sequential samples. Six complete and three partial clinical responses were achieved in a median time of 6 and 3 months, respectively, and confirmed after a median time of 16 months on HAART. 2 patients showed disease progression. A consistent decrease in HIV-1 RNA levels, paralleled by an increase in CD4+ cell counts, was observed in all patients who showed complete or partial clinical response; HIV-1 RNA levels remained persistently high in the two patients who progressed, despite a change in HAART. HHV-8 antibody titres were generally higher in patients with mucosal/visceral involvement compared with patients with limited disease; a decrease in ORF65 antibody titre was significantly associated with a clinical response. These results indicate that HAART is effective for AIDS-related KS; the clinical response correlates with a decrease in plasma HIV-1 RNA levels, an increase in CD4+ lymphocytes, and a decrease in antibodies to ORF65 HHV-8 protein.