The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules such as receptor tyrosine kinases (RTK). Targeting these pathways is often complex and can result in pathway activation depending on the presence of upstream mutations (e.g., Raf inhibitors induce Raf activation in cells with wild type (WT) RAF in the presence of mutant, activated RAS) and rapamycin can induce Akt activation. Targeting with inhibitors directed at two constituents of the same pathway or two different signaling pathways may be a more effective approach. This review will first evaluate potential uses of Raf, MEK, PI3K, Akt and mTOR inhibitors that have been investigated in pre-clinical and clinical investigations and then discuss how cancers can become insensitive to various inhibitors and potential strategies to overcome this resistance.

The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules such as receptor tyrosine kinases (RTK). Certain components of these pathways, RAS, NF1, BRAF, MEK1, DUSP5, PP2A, PIK3CA, PIK3R1, PIK3R4, PIK3R5, IRS4, AKT, NFKB1, MTOR, PTEN, TSC1, and TSC2 may also be activated/inactivated by mutations or epigenetic silencing. Upstream mutations in one signaling pathway or even in downstream components of the same pathway can alter the sensitivity of the cells to certain small molecule inhibitors. These pathways have profound effects on proliferative, apoptotic and differentiation pathways. Dysregulation of components of these cascades can contribute to: resistance to other pathway inhibitors, chemotherapeutic drug resistance, premature aging as well as other diseases. This review will first describe these pathways and discuss how genetic mutations and epigenetic alterations can result in resistance to various inhibitors.

Peripheral arterial disease (PAD) is a common manifestation of atherosclerosis that is associated with systemic in ammation. The aim of our study was to assess whether plasma markers of in ammation increased after exercise in patients with PAD. The study was conducted on two groups of 20 subjects each: one group (mean age 68.4 6 5.09 years) was affected by PAD with claudication, while the other group consisted of healthy controls (66.9 6 6.1 years). Concentrations of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNFa) were determined in plasma, in supernatants and in cells stimulated with 1 mg lipopolysaccharide in all patients. E-selectin (ES), L-selectin (LS) and P-selectin (PS) concentrations and plasma concentrations of VCAM-1 and ICAM-I were also determined. All determinations were performed in patients at rest and after the treadmill exercise. Resting values of soluble mediators were greater in PAD patients than in controls. They increased in both groups after the treadmill test, even if posttreadmill concentrations were signi cantly higher in PAD patients (PAD p < 0.001 or 0.0001, controls p < 0.05 or 0.001).These results con rm that white blood cell activation is characteristic of systemic atherosclerosis and that these in ammation markers increase in conditions of hemodynamic stress.

Previous studies have detected high levels of matrix metalloproteinases (MMPs) in metastatic prostate cancer. In this study, we recruited 40 patients with prostate cancer (PCa): 20 presented organ-confined carcinoma and 20 had metastatic cancer. We also recruited 40 subjects for control groups, 20 with benign prostate hyperplasia (BPH) and 20 healthy males with similar characteristics. All of the patients were monitored at the beginning (time 0) and after 90 days. We analyzed the plasma concentrations of MMP-2, MMP-9, MMP-13, TIMP-1 and the enzyme activity of MMP-2 and MMP-9,using specific ELISA tests. The plasma concentrations of MMP-2, MMP-9 and MMP-13 were higher in PCa patients with metastasis than in the other groups, and in these patients decreased markedly after therapy began. For MMP-2 and MMP-9, greater differences were observed in enzyme activity than in plasma concentrations. TIMP-1 was reduced in PCa patients with metastasis, even if the intergroup differences were not statistically significant. Our results suggest that the plasma concentration and activity of MMPs, in association with PSA determination, could play a role in diagnosis, monitoring therapy and evaluating malignant progression in PCa.

The Yin Yang 1 (YY1) transcription factor has a pivotal role in normal biological processes such as development, differentiation, replication and cell proliferation exerting its effects on a huge number of genes involved in these processes. Mechanisms of YY1 action are related to its ability to initiate, activate, or repress transcription depending upon the context in which it binds. The role of YY1 played in cancer has been recently explored. This article summarizes the most relevant studies focused on YY1 regulation and dwells on the way how its overexpression may affect the clinical behavior of several cancer types. Furthermore, the contribution of the upregulation of YY1 exerted in response to therapeutic-induced apoptosis is discussed.

Deregulation of matrix metalloproteinases (MMPs) is an important factor contributing to the development of vascular lesions. Plasma levels and zymographic activities of MMP-2 and MMP-9 were investigated in type II diabetics with (n ϭ 51) or without (n ϭ 42) peripheral artery disease (PAD) and in normal volunteers (n ϭ 23). Plasma MMP-2 levels were higher in type II diabetics with (p Ͻ 0.01) or without (p Ͼ 0.05) PAD in comparison with normal volunteers. Similarly, type II diabetics with (p Ͻ 0.0001) or without (p Ͼ 0.05) PAD had higher plasma MMP-9 levels than normal volunteers. Plasma zymographic activities of both MMP-2 and MMP-9 were positively correlated with their plasma levels. Plasma MMP-2 zymographic activity was higher in type II diabetics with PAD than type II diabetics without PAD (p Ͼ 0.05). Plasma MMP-9 zymographic activity was higher in type II diabetics with (p Ͻ 0.0001) or without (p Ͻ 0.0001) PAD in comparision with normal volunteers. Together, these results indicate that increased plasma levels and zymographic activities of MMP-2 and MMP-9 may contribute to PAD in type II diabetics. In particular, plasma MMP-9 may be a useful marker for the development of vascular disease in type II diabetics.

Psoriasis is a common cutaneous disorder characterized by abnormal epidermal differentiation, proliferation and inflammation mediated by dermal infiltrates, such as T cells, neutrophils, dendritic cells and macrophages. There are renewed interest in the role of components of the innate immune system. Cytokines such as tumor necrosis factor-• (TNF-•) and interleukin (IL)-6, and-1ß involved in pathogenic phenomena in psoriasis are known as inducers of the acute phase response. Among the large group of acute phase reactants, C-reactive protein (CRP) and fibrinogen are of special interest in psoriasis. The PTX-3, a long pentraxin sharing similarities with the classical short proteins. Thus, considering the numerous biological roles of inflammatory cytokines and their relationship with inflammatory markers, such as CRP and fibrinogen we have investigated the role of PTX3 in psoriasis. To this aim PTX3, TNF-•, IL-6 and IL-1ß in plasma and in monocytic cultures by enzyme linked immunosorbent assay (ELISA) in 44 patients including severe and mild psoriasis were measured. An increased production of PTX3, both in supernatant of purified monocytes and in plasma from patients with severe psoriasis, was found. The significant correlation, between cellular production and plasma levels of PTX3 in psoriasis was found as a sign of cellular activation by monocytes/macrophages that first infiltrate the psoriatic lesion. In severe psoriasis, a significant correlation between psoriasis area and severity index (PASI) score and TNF-• and IL-6 levels in both supernatant of monocytes and plasma was found. In contrast, no correlation was found for IL-1ß. By immunohistochemistry and immunofluorescence, a strong PTX3 staining in fibroblasts, endothelial cells and monocytes/macrophages in severe psoriatic lesional skin was detected. Finally, a positive correlation between PTX3 and disease activity of psoriasis was observed as PASI score was elevated. These findings suggest that PTX3 could be used as a further marker of disease activity of psoriasis.

Mutation of BRAF has been proposed to contribute to melanoma development. However, it remains unclear whether or not BRAF mutation is associated with any particular stage of melanoma progression. Tumor biopsy specimens from patients with melanoma were analyzed to determine whether the frequency of BRAF mutation in metastatic melanoma differed from primary melanoma. BRAF mutation was present in 15 of 23 (61%) patients with primary melanoma and in 7 of 12 (58%) patients with metastatic melanoma. These results suggest that BRAF mutation in melanoma is most likely to occur prior to the development of metastatic disease.