Towards the targeted therapy of melanoma.

Novel anti-cancer treatments use knowledge about the underlying biology of the tumor to find suitable molecular targets. The recent years have seen great advances in understanding the biology of melanoma. In the current review we discuss the most promising molecular targets for melanoma and suggest possible strategies for overcoming resistance.

Defining the conditions for the generation of melanocytes from human embryonic stem cells.

Because of their undifferentiated nature, human embryonic stem cells (hESCs) are an ideal model system for studying both normal human development and the processes that underlie disease. In the current study, we describe an efficient method for differentiating hESCs into a melanocyte population within 4-6 weeks using three growth factors: Wnt3a, endothelin-3, and stem cell factor. The hESC-derived melanocytes expressed melanocyte markers (such as microphthalmia-associated transcription factor and tyrosinase), developed melanosomes, and produced melanin.

Targeting intracellular signaling pathways as a novel strategy in melanoma therapeutics.

Melanoma has been one of the fastest rising malignancies in the last four decades with cases increasing from below 3 per 100,000 people to above 13. Despite worldwide efforts in prevention, diagnosis, and treatment, cases of melanoma continue to rise at an alarming rate of 2.5% annually in the United States.

Targeting the stromal fibroblasts: a novel approach to melanoma therapy.

Classically, cancer is thought of as a genetic disease, where the step-wise acquisition of mutations initiates and drives progression. More recent thinking posits that, although cancers are initiated through genetic mutation, progression is often the result of dynamic interactions between the tumor cells and their surrounding environment.

Selective evolutionary pressure from the tissue microenvironment drives tumor progression.

Cells grow within defined environmental niches and are subject to microenvironmental control. Outside of their niche, the environment is hostile, the normal cells lack appropriate survival signals which leads to anoikis. During tumor development and progression, malignant cells must escape the local tissue control and resist anoikis.

The RAS/RAF/MEK/ERK and PI3K/AKT signaling pathways present molecular targets for the effective treatment of advanced melanoma.

Malignant melanoma is a highly aggressive tumor of the pigment-producing cells in the skin with a rapidly increasing incidence and a poor prognosis for patients with advanced disease that is resistant to current therapeutic concepts. Therefore, the development of novel strategies for treating melanoma are of utmost importance. In melanoma, both the Ras-Raf-MEK-ERK (MAPK) and the PI3K-AKT (AKT) signaling pathways are constitutively activated through multiple mechanisms, and thus exert several key functions in melanoma development and progression.

Adhesion, migration and communication in melanocytes and melanoma.

Under normal conditions, homeostasis determines whether a cell remains quiescent, proliferates, differentiates, or undergoes apoptosis. In this state of homeostasis, keratinocytes control melanocyte growth and behaviour through a complex system of paracrine growth factors and cell-cell adhesion molecules. Alteration of this delicate homeostatic balance and can lead to altered expression of cell-cell adhesion and cell communication molecules and to the development of melanoma.

Up-regulated expression of zonula occludens protein-1 in human melanoma associates with N-cadherin and contributes to invasion and adhesion.

During the process of malignant transformation, nascent melanoma cells escape keratinocyte control through down-regulation of E-cadherin and instead communicate among themselves and with fibroblasts via N-cadherin-based cell-cell contacts. The zonula occludens (ZO) protein-1 is a membrane-associated component of both the tight and adherens junctions found at sites of cell-cell contact. In most cancers, levels of ZO-1 are typically down-regulated, leading to increased motility.

Development of a method for surface and subsurface modeling using force and position sensors.

Subsurface modeling of deformable objects, such as soft tissues and organs, involves the use of non-destructive methods of determining the properties of an object encased by a material. Some of the properties that can be determined from subsurface modeling include: shape, hardness, texture and possibly material. The ability to determine these properties is based on the accuracy of the method used and the properties of the surface encasing the object.

The role of altered cell-cell communication in melanoma progression.

Under normal homeostasis, melanocyte growth and behaviour is tightly controlled by the surrounding keratinocytes. Keratinocytes regulate melanocyte behaviour through a complex system of paracrine growth factors and cell-cell adhesion molecules. Pathological changes, leading to development of malignant melanoma, upset this delicate homeostatic balance and can lead to altered expression of cell-cell adhesion and cell-cell communication molecules.

Functional fitness, disease and independence in community-dwelling older adults in western Wisconsin.

Objective: Older adults are at higher risk for developing chronic conditions such as diabetes, heart disease, or arthritis. Despite the aging process, maintaining independence is a major goal for older adults. Functional fitness has been found to be predictive of one's ability to perform necessary everyday activities needed to maintain independence.

Is knowing enough? Increasing physical activity by wearing a pedometer.

Objective: Physical inactivity is a health concern in the United States with nearly 70% of the population getting inadequate amounts of exercise. We set out to determine if wearing a pedometer could significantly increase awareness and amount of physical activity among female employees at a large health care setting.

Methods: Employees purchased a pedometer, completed a survey, and were encouraged to walk 10,000 steps daily.

Farnesyl transferase inhibitor SCH66336 is cytostatic, pro-apoptotic and enhances chemosensitivity to cisplatin in melanoma cells.

The constitutive activity of a number of growth and cell survival pathways are thought to contribute to the inherent resistance of melanoma to chemotherapy and radiotherapy. Many of these pathways are driven through the small GTPase Ras. Novel drugs such as the farnesyl transferase inhibitors (FTIs) and farnesyl thiosalicylic acid (FTS) interfere with the signaling of oncogenic Ras.

A pivotal role for ERK in the oncogenic behaviour of malignant melanoma?

During the process of oncogenic transformation, melanoma cells escape from normal growth-control mechanisms and acquire the ability to invade surrounding tissues and organs. The Ras/Raf/MEK/ERK pathway is a major pathway involved in the control of growth signals, cell survival and invasion. Melanomas are known to harbour activating mutations of both Ras and BRAF, suggesting that the downstream effector ERK may be playing a major role in the oncogenic behaviour of these tumours.

Differentiation of human melanoma cells through p38 MAP kinase is associated with decreased retinoblastoma protein phosphorylation and cell cycle arrest.

The retinoblastoma protein (pRB), the product of the retinoblastoma gene, is a key regulator of the cell cycle, affecting apoptosis, proliferation and differentiation. Dysregulation of pRB is implicated in the pathogenesis of many cancers, including malignant melanoma. Recently we demonstrated that alpha-melanocyte-stimulating hormone (alpha-MSH)-induced activation of p38 mitogen-activated protein (MAP) kinase leads to differentiation of B16 murine melanoma cells.

Farnesyl thiosalicylic acid inhibits the growth of melanoma cells through a combination of cytostatic and pro-apoptotic effects.

Novel classes of drug that interfere with the signalling of the small G-protein Ras, the so-called Ras antagonists, are showing much promise as novel anti-cancer agents. In this study, we demonstrate that the novel Ras antagonist farnesylthiosalicylic acid (FTS) inhibits the growth of Colo 853 melanoma cells through a combination of cytostatic and pro-apoptotic effects. Furthermore, these phenomena are seen under conditions of cell attachment and in the presence of serum.

The treatment of advanced renal cell cancer with high-dose oral thalidomide.

Thalidomide is reported to suppress levels of several cytokines, angiogenic and growth factors including TNF-alpha, basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6). The resulting anti-angiogenic, immunomodulatory and growth suppressive effects form the rationale for investigating thalidomide in the treatment of malignancies. We have evaluated the use of high-dose oral thalidomide (600 mg daily) in patients with renal carcinoma.

Ligand internalization and recycling by human recombinant somatostatin type 4 (h sst(4)) receptors expressed in CHO-K1 cells.

There is controversy as to whether somatostatin sst(4) receptors internalize. In this study, CHO-K1 cells expressing human sst(4) receptor (CHOsst(4) cells) cells internalized [(125)I]-[(11)Tyr]-SRIF in a time-dependent manner, reaching a steady state at 60 min (1.4+/-0.

The involvement of p38 mitogen-activated protein kinase in the alpha-melanocyte stimulating hormone (alpha-MSH)-induced melanogenic and anti-proliferative effects in B16 murine melanoma cells.

Activation of p38 or p44/42 mitogen-activated protein (MAP) kinases has been shown to trigger differentiation in a number of cell types. The present study has investigated the roles of these kinases in the alpha-melanocyte stimulating hormone (alpha-MSH)-induced melanogenic and proliferative responses in B16 melanoma cells. Treatment of cells with alpha-MSH led to the time-dependent phosphorylation of both p38 and p44/42 MAP kinases.

Screening for personality disorders in a nonclinical population.

Based on the Inventory of Interpersonal Problems (IIP), the IIP-PD and the IIP-C screening scales were developed to distinguish personality disorder (PD) from non-PD and Cluster C from other PD, respectively, in a clinic population. Two studies were conducted to determine (a) validity and reliability of these IIP scales for PD screening in a nonclinical population, (b) specificity of IIP-C for identifying Cluster C, and (c) usefulness of the IIP scales for screening Cluster A. College students were screened using the IIP scales (Study 1, N = 454, Study 2, N = 87).

The pivotal role of phosphoinositide-3 kinase in the human somatostatin sst(4) receptor-mediated stimulation of p44/p42 mitogen-activated protein kinase and extracellular acidification.

We have previously demonstrated in CHO-K1 cells expressing recombinant human sst(4) receptors that somatostatin-induced increases in extracellular acidification are susceptible to a marked desensitisation after pretreatment with somatostatin, but not the somatostatin analogue, L-362855. In the present study, we have examined the human sst(4) receptor-mediated stimulation of p44/p42 mitogen-activated protein (MAP) kinase to determine whether this response is susceptible to a similar agonist-specific desensitisation. Western analysis using phosphospecific antibodies revealed that both somatostatin and L-362855 induced a transient stimulation of MAP kinase which could be desensitised by pretreatment with somatostatin, but not L-362855.

Differential agonist activity of somatostatin and L-362855 at human recombinant sst4 receptors.

1. The operational characteristics of somatostatin (SRIF) sst4 receptors are poorly understood. In this study, we have characterized human recombinant sst4 receptors expressed in CHO cells (CHOsst4) by radioligand binding and microphysiometry.

Protein, fat, and carbohydrate requirements during starvation: anaplerosis and cataplerosis.

The purpose of this work was to clarify the essentiality of glucose production from amino acids in obese subjects undergoing prolonged starvation and to provide an explanation for death after the depletion of lean body mass when some body fat is still available to meet body energy requirements. Five obese subjects fasted for 21 d. Nitrogen balance studies were combined with measurements of blood metabolite and hormone concentrations, indirect calorimetry, determination of body-composition changes, and catheterization techniques.