Reversal of the low-affinity neurotrophin receptor stromal-epithelial expression pattern between benign and malignant human prostate

Reduced expression of the low-affinity p75 neurotrophin receptor (p75(NTR)) occurs in prostate epithelial cells during malignant transformation. Recent studies indicating that the p75(NTR) can transduce signals that induce apoptosis suggest that diminished p75(NTR) in transformed prostate cells may contribute to immortalization. Mutations in the transmembrane domain of the p75(NTR) gene have been associated with decreased p75(NTR) protein expression and may block the ability of the p75(NTR) to induce apoptosis. Therefore, we used Western blot to analyze prostate cancer (PC) cell lines for p75(NTR) protein expression and gene single strand conformation polymorphism (SSCP) analysis and direct DNA sequencing to analyze mutations in the transmembrane domain of the p75(NTR). p75(NTR) Protein was present in all cell lines, and mutations in the p75(NTR) gene were not detected in cDNA derived from any cell line. To define the expression pattern of p75(NTR) in PCs in vivo, we used immunohistochemical techniques to examine tissue specimens from 20 benign, 19 malignant primary, and 14 metastatic prostate specimens. In benign prostate tissues, expression of p75(NTR) was universally detected in basal cells but not in secretory epithelial or stromal cells. In both primary and metastatic PC tissues, p75(NTR) immunoreactivity could not be detected in malignant prostate epithelial cells. However, in contrast to the benign prostate, p75(NTR) protein was expressed in stromal cells surrounding malignant epithelial cells. Stromal p75(NTR) expression was present in 84% (16 of 19) primary and in 86% (12 of 14) metastatic specimens. These data show that in the benign prostate p75(NTR) protein is expressed by basal cells and not stromal cells whereas in malignant prostate p75(NTR) protein is expressed by stromal cells but not prostatic carcinoma cells. Reversal of the p75(NTR) stromal-epithelial pattern of expression between benign and malignant prostate suggests that p75(NTR) may contribute to the development and maintenance of prostate cancer.

BI 836845, a fully human IGF ligand neutralizing antibody, to improve the efficacy of rapamycin by blocking rapamycin-induced AKT activation

3092

Background: Analogs of rapamycin (rapalogs) targeting mammalian target of rapamycin complex 1 (mTORC1) have shown clinical activity in several cancers. Nonetheless, preclinical and clinical data suggest that there may be intrinsic resistance to rapalogs through a feedback loop which activates upstream signaling when mTORC1 is blocked. BI 836845 is a fully human antibody, currently in phase I clinical trials, which potently neutralizes both IGF-1 and IGF-2. We tested whether BI 836845 is able to improve the efficacy of rapamycin by inhibiting upstream signaling in preclinical models. Methods: Cancer cell lines were profiled in vitro and in vivo for sensitivity to BI 836845 and rapamycin, alone or in combination. Mitogenic signaling was examined by measuring levels of phosphorylated AKT (pAKT) using Western blot analysis. IGF bioactivity was determined using a cellular IGF-1R phosphorylation ELISA. Results: The combination of BI 836845 and rapamycin was more effective than either agent alone at inhibiting the proliferation of Ewing’s sarcoma cells cultured in vitro as well as in a nude mouse xenograft model in vivo. Analysis of cell signaling upstream of mTOR demonstrated that treatment with rapamycin alone resulted in elevated pAKT, indicating feedback loop activation. BI 836845 treatment alone or in combination with rapamycin inhibited AKT phosphorylation, demonstrating that the rapamycin-induced increase in pAKT was due to elevated IGF bioactivity. Consistent with this we demonstrated that rapamycin increased IGF bioactivity in mice and that this could be inhibited by BI 836845. We extended these studies to include other cancer cell lines and profiled the correlation between improved efficacy of the combination with BI 836845 inhibition of rapamycin-induced feedback. A correlation has been observed for cancer cells derived from several indications. Conclusions: Rapamycin treatment increases AKT activation via elevated IGF ligand bioactivity. This effect can be inhibited by BI 836845, thus explaining the improved pre-clinical efficacy seen when both agents are combined. These data provide a rationale for the clinical combination of rapalogs and BI 836845.

Spontaneous adverse event reports of Stevens-Johnson syndrome/toxic epidermal necrolysis: detecting associations with medications

PURPOSE

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are medically serious skin reactions that are often drug induced. The mainstay of therapy and future prevention is to discontinue and avoid the use of the suspected inducing drug. However, many cases of SJS/TEN occur in patients who are taking multiple medications, and it is often difficult to determine which drug to stop. This analysis was conducted to identify drugs that were most associated with SJS/TEN in the US Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) database and to identify medications that were likely innocent bystanders.

METHODS

A Multi-item Gamma Poisson Shrinker value with an EB05 ≥ 2 was considered a disproportional increase in reporting frequency (at least two times higher than expected). The identified drugs with reporting frequency of SJS/TEN in the US FDA AERS database were then compared to the EuroSCAR (European case-control surveillance of severe cutaneous adverse reactions) study results as a reference to define signals. The EB05s were calculated as a cumulative relative reporting frequency from 1968 to 3Q2009.

RESULTS

Fifty drugs were identified as being associated with SJS/TEN. This included 12 "highly suspect" drugs and 36 "suspect" drugs. Meloxicam was the only drug that appeared on the "highly suspect" list from EuroSCAR that did not show a disproportional increase in relative reporting frequency (EB05 = 0.734). In addition, several drugs did not have an association with SJS/TEN (EB05 < 2).

CONCLUSIONS

There was good concordance between the reporting frequencies observed in the FDA AERS database and the published risk estimation of medications implicated in SJS/TEN.

Topotecan Weekly Versus Conventional 5-Day Schedule in Patients With Platinum-Resistant Ovarian Cancer: a randomized multicenter phase II trial of the North-Eastern German Society of Gynecological Oncology Ovarian Cancer Study Group

PURPOSE

Weekly administration of topotecan (Tw) is less toxic and widely considered a better treatment option than conventional 5-day therapy (Tc) in women with platinum-resistant recurrent ovarian cancer. We conducted a randomized phase II trial (TOWER [Topotecan Weekly Versus Conventional 5-Day Schedule in Patients With Platinum-Resistant Ovarian Cancer]) to better define the ratio between benefits and risks with either treatment approach.

PATIENTS AND METHODS

Patients were randomly assigned to two independent two-stage protocols of Tw (4 mg/m(2)/wk administered on days 1, 8, and 15) or Tc (1.25 mg/m(2)/d on days 1 to 5). We evaluated risk ratios (RRs) for the primary end point of clinical benefit (complete response, partial response, and stable disease), the duration of progression-free survival (PFS) and overall survival (OS), associated hazard ratios (HRs), and RRs of toxicity with 95% CIs.

RESULTS

In total, 194 patients were randomly assigned at 54 centers to Tw (n = 97) or Tc (n = 97). Clinical benefit was observed in 36 of 76 (47%; 95% CI, 36% to 59%) Tw and 46 of 80 (58%; 95% CI, 46% to 68%) Tc patients (RR, 1.21; 95% CI, 0.90 to 1.64; P = .205). Patients in the Tw group had a slightly shorter PFS (HR, 1.29; 95% CI, 0.96 to 1.76) but similar OS (HR, 1.04; 95% CI, 0.74 to 1.45) compared with Tc. Tw was associated with significantly lower risks of anemia (RR, 0.35; 95% CI, 0.16 to 0.79), neutropenia (RR, 0.38; 95% CI, 0.23 to 0.65), and thrombocytopenia (RR, 0.23; 95% CI, 0.09 to 0.57).

CONCLUSION

With regard to effectiveness in terms of response and PFS, Tc remains the standard of care in patients with platinum-resistant recurrent ovarian cancer. However, comparable OS rates and a favorable toxicity profile make Tw another viable treatment option in this setting.

Topotecan in cervical cancer

Recurrent and advanced cervical cancers are associated with high mortality and a lack of effective treatment options, especially for women who are poor candidates for surgery or radiation therapy. The broad clinical effectiveness and manageable toxicity of topotecan in other human malignancies as well as promising recent study results suggest that it is highly effective in treating cervical tumors. We therefore conducted a systematic review on the studies using topotecan in cervical cancer. Seven phase I-III clinical trials using topotecan, both as a single agent and in combination with cisplatin or paclitaxel, in patients with recurrent or advanced carcinoma of the cervix were reviewed. Data from two studies in which topotecan was used in combination with radiotherapy for induction therapy were also evaluated. Although single-agent cisplatin-based chemoradiotherapy is the standard of care for high-risk or locally advanced cervical cancer, topotecan, when used concurrently with cisplatin and/or radiation therapy, produces high objective response rates and prolonged survival. Gynecologic Oncology Group (GOG) Protocol 179 for the first time showed significantly improved overall survival and progression-free survival in a combination therapy for advanced cervical cancer compared to cisplatin alone. Recent data suggest that topotecan, when used concurrently with cisplatin, may be the new standard of care for the management of recurrent or advanced cervical cancer. Ongoing phase III studies (GOG-204, AGO-Zervix-1) will compare this combination with other cisplatin-containing and cisplatin-free combinations. Moreover, further evaluation of topotecan appears to be warranted in conjunction with radiotherapy and in the neoadjuvant setting as well as in combination with novel biologic agents.

[Detection of lymph node metastases of malignant melanoma by palpation and ultrasound]

BACKGROUND AND PURPOSE

Early detection of metastases of malignant melanoma has therapeutic implications. The aim of this study was to evaluate palpation and ultrasound examination in the diagnostics of lymph node metastases in locally advanced melanoma.

PATIENTS AND METHODS

83 patients suffering from melanoma (Clark level IV or V) were examined for lymph node metastases by palpation and sonography. Findings were compared to histopathologic results after lymph node extirpation if available or the findings at the next follow-up visit.

RESULTS

Lymph node metastases were confirmed histopathologically in 14 patients at the first study visit, in three others at the control visit. Sensitivity, specificity, positive and negative predictive values of palpation for the detection of metastases or suspicious nodes with increasing volume at follow-up in this population were 65%, 81%, 48%, and 89%, and of ultrasound 100%, 66%, 45%, and 100%, respectively.

CONCLUSION

Sonography of lymph nodes should be included as a standard procedure in the detection of metastases of locally advanced malignant melanoma.

Axis of evil: molecular mechanisms of cancer metastasis

Although the genetic basis of tumorigenesis may vary greatly between different cancer types, the cellular and molecular steps required for metastasis are similar for all cancer cells. Not surprisingly, the molecular mechanisms that propel invasive growth and metastasis are also found in embryonic development, and to a less perpetual extent, in adult tissue repair processes. It is increasingly apparent that the stromal microenvironment, in which neoplastic cells develop, profoundly influences many steps of cancer progression, including the ability of tumor cells to metastasize. In carcinomas, the influences of the microenvironment are mediated, in large part, by bidirectional interactions (adhesion, survival, proteolysis, migration, immune escape mechanisms lymph-/angiogenesis, and homing on target organs) between epithelial tumor cells and neighboring stromal cells, such as fibroblasts as well as endothelial and immune cells. In this review, we summarize recent advances in understanding the molecular mechanisms that govern this frequently lethal metastatic progression along an axis from primary tumor to regional lymph nodes to distant organ sites. Affected proteins include growth factor signaling molecules, chemokines, cell-cell adhesion molecules (cadherins, integrins) as well as extracellular proteases (matrix metalloproteinases). We then discuss promising new therapeutic approaches targeting the microenvironment. We note, however, that there is still too little knowledge of how the many events are coordinated and integrated by the cancer cell, with conspiratorial help by the stromal component of the host. Before drug development can proceed with a legitimate chance of success, significant gaps in basic knowledge need to be filled.

Reciprocal regulation of MelCAM and AKT in human melanoma

Alteration in the expression of invasion/metastasis-related melanoma cell adhesion molecule (MelCAM) is strongly associated with the acquisition of malignancy by human melanoma. However, little is known about the molecular and biochemical mechanisms that regulate the expression and function of MelCAM, or its downstream signaling transduction. In this study, we show that there is a reciprocal regulation loop between AKT and MelCAM. Pharmacological inhibition of AKT in human melanoma cell lines substantially reduced the expression of MelCAM. Overexpression of constitutively active AKT upregulated the levels of MelCAM in melanoma cell lines, whereas expression of a dominant-negative PI-3 kinase downregulated MelCAM. On the other hand, overexpression of MelCAM activated endogenous AKT and inhibited proapoptotic protein BAD in melanoma cells, leading to increased survival under stress conditions. Constitutive activation of AKT was observed in most melanoma cell lines and tumor samples of different progression stages. These data link AKT activation with MelCAM expression, and implicate that intervention of MelCAM-AKT signaling axis in melanoma is a potential therapeutical approach.

Treatment of Old World cutaneous leishmaniasis with intralesionally injected meglumine antimoniate using a Dermojet device

Pentavalent antimonial compounds, the mainstay in the treatment of the various forms of leishmaniasis, have considerable toxicity, are difficult to administer and expensive. We describe a safe and efficient therapeutic modality using a spring-loaded and air-powered device for the intralesional injection of a high-velocity meglumine antimoniate microspray in a patient with cutaneous leishmaniasis.

Orofacial granulomatosis as the initial presentation of Crohn's disease in an adolescent

Orofacial granulomatosis (OFG) is a rare and heterogeneous clinical condition that presents with chronic swelling of the oral or facial tissues due to granulomatous inflammation. It is histologically characterized by noncaseating giant cell granulomata and epithelioid histiocytes. OFG includes the previously recognized clinical entities of Melkersson-Rosenthal syndrome and cheilitis granulomatosa (Miescher's cheilitis). A consistently effective medical treatment is not currently available. We describe an adolescent patient with a history of recurrent orofacial swelling preceding gastrointestinal symptoms by several years. He exhibited clinical and histological changes consistent with the diagnosis of OFG. It was resistant to standard therapies such as topical corticosteroids. Thorough history taking and clinical examination suggested Crohn's disease (CD), and further tests confirmed the diagnosis. The patient improved promptly after initiating oral treatment for CD with mesalazine and prednisolone. We conclude that OFG may be under- or misdiagnosed since the clinical manifestation may be misleading and its course is independent of or even preceding CD. Thus, patients with OFG should be asked about gastrointestinal symptoms consistent with CD. Those with suspicious symptoms should undergo a careful gastrointestinal evaluation, possibly including enteroclysis and complete gastrointestinal endoscopic examination, especially when the patient's history is conspicuous.

Function and regulation of melanoma-stromal fibroblast interactions: when seeds meet soil

Melanoma development and progression not only involve genetic and epigenetic changes that take place within the melanocytic cells, but also involve processes that are determined collectively by contextual factors including intercellular adhesions and communications. In this review, we focus on melanoma-stromal fibroblast crosstalk by direct cell-cell contact and by growth factors/cytokines/chemokines interacting with their respective receptors. The interactions between melanoma cells and stromal fibroblasts create a context that promotes tumor growth, migration/invasion, and angiogenesis. An understanding of this process and developing new experimental and screening models are of great importance for the development of effective therapeutical strategies to treat melanoma.

Benign Degos' disease developing during pregnancy and followed for 10 years

Degos' disease, or malignant atrophic papulosis, is a rare and often fatal multisystem vasculopathy of unknown etiology. The cutaneous manifestations comprise erythematous papules, which heal to leave scars with a pathognomonic central porcelain-white atrophic area and a peripheral telangiectatic rim. Involvement of the gastrointestinal tract is observed in 50% of cases, with intestinal perforation being the most common cause of death. Other organ systems can also be affected; 20% of cases involve the central nervous system. Systemic manifestations usually develop from weeks to years after onset of skin lesions or, in rare instances, may precede skin lesions. In the patient with Degos' disease reported in this article, the characteristic skin lesions developed during pregnancy, a precipitating event not previously reported. She has survived an unusually long time (10 years) without visceral or neurological involvement, despite florid cutaneous lesions. Moreover, we could detect the presence of antiphospholipid antibodies, the significance of which are currently unclear. These observations therefore confirm that there may be a strictly cutaneous form of Degos' disease with a favourable prognosis.

Stroma formation and angiogenesis by overexpression of growth factors, cytokines, and proteolytic enzymes in human skin grafted to SCID mice

Reorganization of skin during wound healing, inflammatory disorders, or cancer growth is the result of expression changes of multiple genes associated with tissue morphogenesis. We wanted to identify proteins involved in skin remodeling and select those that may be targeted for agonistic or antagonist therapeutic approaches in various disease processes. Full-thickness human skin was grafted to severe combined immunodeficient mice and injected intradermally with 38 different adenoviral vectors inserted with 37 different genes coding for growth factors, cytokines, proteolytic enzymes and their inhibitors, adhesion receptors, oncogenes, and tumor suppressor genes. Responses were characterized for infiltration of inflammatory cells, vascular density, matrix formation, fibroblast-like cell proliferation, and epidermal hyperplasia. Of the 17 growth factor vectors, 16 induced histological changes in human skin. Members of the VEGF and angiopoietin families induced neovascularization. PDGFs and TGF-betas stimulated connective tissue formation, and the chemokines IL-8 and MCP-1 attracted inflammatory neutrophils and monocytes, respectively. The serine protease uPA induced a vascular response similar to that of VEGF. Vectors with adhesion receptors, oncogenes and tumor suppressor genes had, with few exceptions, little effects on skin architecture. The overall results suggest that adenoviral vectors can effectively remodel the architecture of human skin for studies in morphogenesis, inflammatory skin disorders, wound healing, and cancer development.

[From the New World. Louis A. Duhring and dermatitis herpetiformis]

Louis Adolphus Duhring (born December 23, 1845) died in Philadelphia, the city of his birth and life work, on May 8, 1913. After medical school, he studied for two years in dermatology departments in London, Paris and Vienna. As a student in Vienna, he was under the tutelage of Ferdinand von Hebra, when the brilliant clinician and teacher was at the zenith of his fame. Duhring's series of 18 papers--published between 1884 and 1891--gave him an important and recognized position as one of the leading dermatological thinkers of the world. These publications described the skin disease which he named "dermatitis herpetiformis" (Duhring's disease). His assertion that dermatitis herpetiformis was a distinct dermatological disease process aroused at first considerable opposition. Moriz Kaposi, at that time the doyen of the Vienna school of dermatology, attacked his views with vigor and tenacity. Louis A. Duhring--this modest, unassuming, quiet-working, gentlemanly physician--made monumental contributions to American dermatology and played a significant role in establishing Philadelphia as one of the great centers of dermatologic activity.

Differential response of primary and metastatic melanomas to neutrophils attracted by IL-8

IL-8 is a strong chemoattractant for neutrophils, and it is constitutively produced by many tumors, including human melanomas. To determine the biologic importance of IL-8 for melanoma cells from primary and metastatic lesions, we transduced selected cell lines constitutively producing low levels of IL-8 with IL-8 cDNA using a replication-deficient adenoviral vector. Nontumorigenic SBcl2 primary melanoma cells formed tumors when transduced with increasing plaque-forming units of IL-8 per cell. However, at high IL-8 transduction levels (100 ng/ml/10(5) cells in 48 hr), tumor growth was impaired due to massive neutrophil infiltration. A similar biphasic response was observed in WM115 primary melanomas, which are tumorigenic but not metastatic. Depletion of neutrophils with an antibody that blocks the accumulation of granulocytes at the site of inflammation enabled transduced primary melanomas secreting high levels of IL-8 to survive and grow. In contrast, highly tumorigenic and metastatic 451Lu cells showed marked increases in tumor growth and number of metastatic foci in the lungs depending on the expression levels of IL-8. Cytotoxicity assays with isolated neutrophils confirmed the preferential killing of primary over metastatic melanoma cells. SBcl2 cells stimulated by IL-8 to form tumors in immunodeficient mice were induced to produce VEGF, suggesting that the angiogenic response is enhanced due to increased growth factor production. Our results demonstrate that nontumorigenic primary melanomas depend on IL-8 stimulation in vivo for growth and that tumor growth depends on the level of neutrophil infiltration. Metastatic melanomas proliferate in vivo independently of infiltrating neutrophils.

Eruptive multiple lentigo-maligna-like lesions in a patient undergoing chemotherapy with an oral 5-fluorouracil prodrug for metastasizing colorectal carcinoma: a lesson for the pathogenesis of malignant melanoma?

Induction of multiple eruptive dermal and atypical melanocytic naevi has frequently been reported in children with malignant haematological diseases and chemotherapy-induced immunosuppression. This is the first report of an adult patient to develop multiple eruptive melanocytic skin lesions while undergoing chemotherapy with an oral 5-fluorouracil prodrug for metastasizing cancer. Our observation adds further evidence to the link between systemic (iatrogenic or intrinsic) immunosuppression and the induction of melanocyte proliferation and transformation.

Cell-surface proteolysis, growth factor activation and intercellular communication in the progression of melanoma

Normal skin architecture and melanocyte function is maintained by a dynamic interplay between the melanocytes themselves, the epithelial cells between which they are interspersed, and their microenvironment. The microenvironment consists of the extracellular matrix, fibroblasts, migratory immune cells, and neural elements supported by a vascular network, all within a milieu of cytokines, growth factors, and bioactive peptides as well as proteolytic enzymes. Cells interact with the microenvironment via complex autocrine and paracrine mechanisms. Proteolytic enzymes in melanoma may activate or release growth factors from the microenvironment or act directly on the microenvironment itself, thereby facilitating angiogenesis or tumor cell migration. This review summarizes recent findings regarding the expression, structure and function of proteolytic enzymes at or near the cell surface in cell-cell and cell-stroma interactions during melanoma progression. Cell-surface (membrane) peptidases are a multi-functional group of ectoenzymes that have been implicated in the control of growth and differentiation of many cellular systems. The potential, but yet speculative, role of other membrane-bound molecules, such as multifunctional surface proteins with adhesion and protease activity (ADAM gene family) or the ephrin/Eph receptor protein kinases in the pathogenesis of melanoma are discussed.

Multiple, bilateral and painful ear nodules of the anthelices: a variant of chondrodermatitis nodularis?

A case of a distinctive clinicopathologic condition of the ear cartilage is presented, characterized by multiple, bilateral and painful nodules of the anthelices without epidermal involvement. Histologically, there was a peri-chondrial lymphohistiocytic infiltrate and a small focus of degenerate, basophilic cartilage as well as cystic chondromalacia containing an amorphous mass. This condition is both clinically and histopathologically distinct from other causes of ear nodules, although the lesions seen in our patient exhibit features of chondrodermatitis nodularis helices and therefore could well be a variant of the latter.