Downregulation of cell cycle modulators p21, p27, p53, Rb and proapoptotic Bcl-2-related proteins Bax and Bak in cutaneous melanoma is associated with worse patient prognosis: preliminary findings

Nuclear Blebbing Frequency in Tobacco-Induced Oral Potentially Malignant Disorders: A Pilot Study

INTRODUCTION

Tobacco contains several genotoxic agents including N-nitrosamine which has the potential to cause significant nuclear damage. Nuclear blebbing is a form of protrusion on the nuclear membrane and could potentially be caused by tobacco-induced genotoxicity and is closely associated with malignancy. Thus, the present study aimed to assess if tobacco-associated oral potentially malignant disorders including oral submucous fibrosis (OSF) and oral leukoplakia have a higher nuclear blebbing frequency than patients with normal oral mucosa with no history of tobacco use.

METHODS

The sample consisted of patients with OSF (n = 30) and oral leukoplakia (n = 10) and normal oral mucosa (n = 10). Exfoliated cells collected from the study groups were smeared on a clean microscopic slide and stained by May-Grunwald-Giemsa stain. A baseline frequency of nuclear blebbing was evaluated using a bright-field microscope with a ×100 objective. The number of nuclear blebbing per 1,000 epithelial cells was recorded and expressed in percentage. ANOVA, the Mann-Whitney U test, and Spearman's correlation were used to analyze the data.

RESULTS

The mean rank of distribution of nuclear blebbing showed significant difference between all 3 groups, with the highest frequency noted in leukoplakia, followed by oral submucous and normal oral mucosa. Within OSF, the frequency of nuclear blebbing significantly increased from early stage to advanced stage. In OSF, a statistically significant positive linear correlation was noted between duration (in years), frequency (per day) of tobacco use, clinical grading, and nuclear blebbing.

DISCUSSION/CONCLUSIONS

The frequency of nuclear blebbing was significantly higher in oral potentially malignant disorders than normal mucosa. Nuclear blebbing also exhibited a strong dose- and time-dependent correlation with tobacco usage and clinical staging in OSF. The nuclear blebbing frequency could be a noninvasive, economic tool to assess malignant risk in tobacco-induced oral potentially malignant disorders.

Loss of Concurrent Regulation of the Expression of BIF-1, BAX, and Beclin-1 in Primary and Metastatic Melanoma

Melanoma is one of the most aggressive and drug-resistant cancers. Despite novel promising therapeutic strategies, the prognosis of metastatic melanoma patients remains poor and it is often associated with high relapse rates. Endophilin B1, also known as BIF-1, is a multifunctional protein involved in several biological processes such as autophagy and apoptosis. BIF-1 promotes apoptosis through binding to BAX and its translocation to the mitochondrial outer membrane. On the other hand, BIF-1 can interact with Beclin-1 through UVRAG to promote autophagy. Several reports suggest an ambiguous role of BIF-1 in cancer development and progression. For example, it has been demonstrated that the expression of BIF-1 is reduced in both primary and metastatic melanoma and that the reduction of BIF-1 expression is associated with reduced overall survival of melanoma patients. Here we show that the expression of Beclin-1 and active form of BAX are also reduced in the melanoma patients. However, while we observed strong positive correlations between the expression of BIF-1 and Beclin-1 as well as between BIF-1 and BAX in benign nevi, these correlations were lost in the primary and metastatic melanoma cells. These data indicate disruption in the proximal molecular mechanisms which regulate expression of BIF-1, Beclin-1, and BAX in the primary and metastatic melanoma.

The Future of Personalized Medicine: One Step Melanoma Surgery

The divergent, personalized approach in the surgical treatment of cutaneous melanoma is the one in which the treatment of the neoplasm differs from that proposed within the generally accepted standards or guidelines. According to their presumption, guidelines are not obligatory for the treatment of a certain type of disease and cannot replace the judgment of the clinician. Which to a large extent determines the freedom (or possible one) of the clinician‘s action regarding the „personalization“ in the choice of a new, divergent therapy. It is interesting, for example, that the occurrence of locoregional recurrences in patients with melanoma after guideline therapy insures clinicians against both criticism of treatment choice and the end results. However, the lack of recurrences after innovative/personalized surgical treatment of cutaneous melanoma is accompanied for unknown reasons by a serious dose of unwarranted criticism. The fact is that a personalized surgical approach in the treatment of skin melanomas and the recommended by AJCC guidelines approach lead to exactly the same end results and that should not be ignored. The difference lies in the fact that this end result can be achieved by one step melanoma surgery (OSMS), for example, which is carried out in a single surgical session. Several advantages of OSMS can be noted: 1) it provides high efficiency in a short time, even in the initial stage of the disease, 2) it is cost-effective, and 3) according to initial clinical observations we have a much lower to no propensity for locoregional relapses.

Melanoma in the liver: Oxidative stress and the mechanisms of metastatic cell survival

Metastatic melanoma is a fatal disease with a rapid systemic dissemination. The most frequent target sites are the liver, bone, and brain. Melanoma metastases represent a heterogeneous cell population, which associates with genomic instability and resistance to therapy. Interaction of melanoma cells with the hepatic sinusoidal endothelium initiates a signaling cascade involving cytokines, growth factors, bioactive lipids, and reactive oxygen and nitrogen species produced by the cancer cell, the endothelium, and also by different immune cells. Endothelial cell-derived NO and H₂O₂ and the action of immune cells cause the death of most melanoma cells that reach the hepatic microvascularization. Surviving melanoma cells attached to the endothelium of pre-capillary arterioles or sinusoids may follow two mechanisms of extravasation: a) migration through vessel fenestrae or b) intravascular proliferation followed by vessel rupture and microinflammation. Invading melanoma cells first form micrometastases within the normal lobular hepatic architecture via a mechanism regulated by cross-talk with the stroma and multiple microenvironment-related molecular signals. In this review special emphasis is placed on neuroendocrine (systemic) mechanisms as potential promoters of liver metastatic growth. Growing metastatic cells undergo functional and metabolic changes that increase their capacity to withstand oxidative/nitrosative stress, which favors their survival. This adaptive process also involves upregulation of Bcl-2-related antideath mechanisms, which seems to lead to the generation of more resistant cell subclones.

Low expression of pro-apoptotic proteins Bax, Bak and Smac indicates prolonged progression-free survival in chemotherapy-treated metastatic melanoma

Despite the introduction of novel targeted therapies, chemotherapy still remains the primary treatment for metastatic melanoma in poorly funded healthcare environments or in case of disease relapse, with no reliable molecular markers for progression-free survival (PFS) available. As chemotherapy primarily eliminates cancer cells by apoptosis, we here evaluated if the expression of key apoptosis regulators (Bax, Bak, Bcl-2, Bcl-xL, Smac, Procaspase-9, Apaf-1, Procaspase-3 and XIAP) allows prognosticating PFS in stage III/IV melanoma patients. Following antibody validation, marker expression was determined by automated and manual scoring of immunohistochemically stained tissue microarrays (TMAs) constructed from treatment-naive metastatic melanoma biopsies. Interestingly and counter-intuitively, low expression of the pro-apoptotic proteins Bax, Bak and Smac indicated better prognosis (log-rank p < 0.0001, p = 0.0301 and p = 0.0227 for automated and p = 0.0422, p = 0.0410 and p = 0.0073 for manual scoring). These findings were independently validated in the cancer genome atlas (TCGA) metastatic melanoma cohort (TCGA-SKCM) at transcript level (log-rank p = 0.0004, p = 0.0104 and p = 0.0377). Taking expression heterogeneity between the markers in individual tumour samples into account allowed defining combinatorial Bax, Bak, Smac signatures that were associated with significantly increased PFS (p = 0.0002 and p = 0.0028 at protein and transcript level, respectively). Furthermore, combined low expression of Bax, Bak and Smac allowed predicting prolonged PFS (> 12 months) on a case-by-case basis (area under the receiver operating characteristic curve (ROC AUC) = 0.79). Taken together, our results therefore suggest that Bax, Bak and Smac jointly define a signature with potential clinical utility in chemotherapy-treated metastatic melanoma.

Downregulated long non-coding RNA LINC00899 inhibits invasion and migration of spinal ependymoma cells via RBL2-dependent FoxO pathway

This study is aimed to clarify the potential role of lncRNA LINC00899 in invasion and migration of spinal ependymoma cells through the FoxO pathway via RBL2. Spinal ependymoma related chip data (GSE50161 and GSE66354) was initially downloaded and differentially expressed lncRNAs were screened out. Fifty-eight cases of spinal ependymoma and normal ependymal tissues were collected. The effects of LINC00899 and RBL2 on the spinal ependymoma cell migration and invasion were determined using the third generation spinal ependymoma cells and transfection with LINC00899 vector, siRNA-LINC00899 and siRNA-RBL2. The expression of LINC00899, pathway and cell proliferation- and apoptosis-related factors was determined. Finally, we also detected cell proliferation, migration, invasion, cycle and apoptosis after transfection. Our results showed that LINC00899 was up-regulated in spinal ependymoma and RBL2 was confirmed as a target gene of LINC00899 and found to be involved in regulation of FoxO pathway. LINC00899 expression increased in spinal ependymoma tissues whereas RBL2 expression decreased. Moreover, we found that siRNA-LINC00899 could elevate RBL2, p21, p27 and Bax levels, decrease FoxO, Bcl-2, Vimentin, Annexin levels, reduced cell proliferation, migration and invasion and enhanced apoptosis. Taken together, our study suggests that down-regulated LINC00899 exerts anti-oncogenic effects on spinal ependymoma via RBL2-dependent FoxO, which provides a novel therapeutic target for the treatment of spinal ependymomas.

High-Risk BCC Of the Lower Eyelid in Patient with Presternal Located Cutaneous Melanoma and BCC Of the Shoulder: Melolabial Advancement Flap Combined with Undermining Surgical Approach As Promising Complex One Step Treatment Option!

BACKGROUND:

It is assumed that the occurrence of keratinocyte and melanocytic tumours is multifactorial driven. Certain risk factors such as solar radiation, p53 protein and Melanocortin-1 receptor (MC1R) prove to be common to their development, which at the same time shows that their simultaneous manifestation in the same patients, for example, is quite possible. Such a manifestation could be observed as collision tumours within the same solitary lesion or as a simultaneous occurrence within two completely different lesions that are clearly distinguished from one another.

CASE REPORT:

An 85-year-old patient is presented with three primary cutaneous tumours located in region presternal, infraorbital sinistra and scapularis extra. The lesions were removed during a single surgical session. For the high-risk basal cell carcinoma (BCC) in the lower eyelid, the so-called melolabial advancement flap was applied, and for the tumours located in the other two areas, the undermining surgical approach was applied. The subsequent histological analysis found that the case referred to two keratinocyte tumours (BCC) and one melanocyte tumour (cutaneous melanoma).

CONCLUSIONS:

The patient presented is interesting with regard to 1) the simultaneous presentation of three primaries with different localization (so far not described in the world literature, namely 2 basal cell carcinomas and one melanoma in the same patient concurrently), 2) one of the basal cell tumours belongs to the group of high-risk (according to the localization) and meanwhile advanced BCC (according to the infiltration degree of the underlying tissue-infiltration of the musculature) and 3) their simultaneous successful surgical treatment in a single surgical session under local anaesthesia.

Schizophrenia as Potential Trigger for Melanoma Development and Progression! The Psycho-Neuro-Endocrine-Oncology (P.N.E.O) Network!

BACKGROUND

Skin, nervous tissue, dopamine and melanoma share a common neuroectodermal origin. Hence, processes that modulate nervous tissue formation, patient mental status, motor regulation of individuals, and skin cancerogenesis are inextricably linked. Psycho-neuro-endocrine oncology (or dermato-oncology), i.e. P.N.E.O., is a new model or trend in medicine and science presented for the first time in the world literature by us, that aims to examine the relationship between the mental state, the hormones and the malignant transformation. Schizophrenia and Parkinson's disease are the two main patterns of disease where the main symptoms are related to dopamine levels in the human body. According to our analyses of the available literature, the amount of dopamine is related to the incidence of melanocytic or non-melanocytic cutaneous tumours in patients with central nervous system diseases and those affecting the motor function and coordination. Such patterns of interaction are extremely indicative of the elucidation of the ubiquitous hypothesis or statement: "My illness is on a mental basis, caused by stress …".

CASE PRESENTATION

We present a 44-year-old patient with untreated schizophrenia for approximately 25 years, associated with advanced acral localised melanoma. Schizophrenia is generally associated with a higher level of dopamine, which is also a key precursor to melanin synthesis. After a careful analysis of all literature on melanoma in patients with 1) treated and untreated schizophrenia, 2) those with untreated and untreated forms of Parkinson's disease, it would be logical to conclude that the high level of dopamine in the described patient groups is a risk factor for the development of melanoma.

CONCLUSIONS

The possible mechanisms for the occurrence of malignant melanoma within the so-called psycho/neuro/endocrine oncology (P.N.E.O.), as well as the effective methods of prevention, are under discussion.

Costunolide induces G1/S phase arrest and activates mitochondrial-mediated apoptotic pathways in SK-MES 1 human lung squamous carcinoma cells

Despite the availability of several therapeutic options, a safer and more effective modality strategy is required for the treatment of lung cancer. Costunolide, a sesquiterpene lactone which isolated from the Saussurea lappa, has potent anticancer properties. In the present study, the effects of costunolide on cell viability, the cell cycle and apoptosis in SK-MES-1 human lung squamous carcinoma cells were investigated. Costunolide induced morphological changes and inhibited growth of SK-MES-1 cells growth. Flow cytometric analysis data demonstrated that costunolide significantly induced apoptosis of SK-MES-1 cells and induced cell cycle arrest at G1/S phase in a dose-dependent manner. Through upregulation in the expression of p53 and Bax, and downregulation in the expression of Bcl-2 and activation of caspase-3, costunolide-induced apoptosis was confirmed by western blot analysis. In addition, the significant loss of mitochondrial membrane potential indicated that costunolide may induce apoptosis via the mitochondria-dependent pathway in SK-MES-1 cells. These results highlight the potential effects of costunolide as an anti-cancer agent in a human lung squamous carcinoma cell line.

The differential susceptibilities of MCF-7 and MDA-MB-231 cells to the cytotoxic effects of curcumin are associated with the PI3K/Akt-SKP2-Cip/Kips pathway

Background

The mechanism underlying the differential cytotoxicity of curcumin in various cancer types, however, remains largely unclear. The aims of this study is to examine the concentration- and time-related effects of curcumin on two different breast cancer cells, MCF-7 and MDA-MB-231, and investigated the functional changes induced by curcumin treatment, as well as their relationship to the PI3K/Akt-SKP2-Cip/Kips pathway.

Methods

First, WST-1 and clonogenic assay were performed to determine the cytotoxicity of curcumin in MCF-7 and MDA-MB-231 cells. Then, the expression of CDK interacting protein/Kinase inhibitory protein (Cip/Kips) members (p27, p21 and p57) and S-phase kinase-associated protein-2 (SKP2) was investigated by QRT PCR and Western Blotting. Curcumin’s effect on PI3K (phosphatidylinositol 3-kinase) /Akt and its substrates Foxo1 and Foxo3a were then studied by Western Blotting. Small interfering RNAs (siRNAs) targeting SKP2 was used to explore the relationship between SKP2 and Cip/Kips members. Finally, WST-1 assay was tested to explore the concomitant treatment with curcumin and the inhibition of PKB or SKP2 signaling on curcumin sensitivity in MCF-7 and MDA-MB-231 cells.

Results

We demonstrated MCF-7 and MDA-MB-231 cells exhibited differential responses to curcumin by WST-1 and clonogenic assay (MDA-MB-231 cells was sensitive, and MCF-7 cells was resistant), which were found to be related to the differential curcumin-mediated regulation of SKP2-Cip/Kips (p21 and p27 but not p57) signaling. The differential cellular responses were further linked to the converse effects of curcumin on PI3K/Akt and its substrates Foxo1 and Foxo3a. Importantly, PI3K inhibitor wortmannin could counteract both curcumin-induced phosphorylation of Akt and up-regulation of SKP2 in MCF-7 cells. Subsequent WST-1 assay demonstrated concomitant treatment with curcumin and wortmannin or SKP2 siRNA not only further augmented curcumin sensitivity in MDA-MB-231 cells but also overcame curcumin resistance in MCF-7 cells.

Conclusions

Our study established PI3K/Akt-SKP2-Cip/Kips signaling pathway is involved in the mechanism of action of curcumin and revealed that the discrepant modulation of this pathway by curcumin is responsible for the differential susceptibilities of these two cell types to curcumin.

Pathways of tumor development and progression in drug-induced nonmelanoma skin cancer: a new hope or the next great confusion?

The factors that lead to the clinical manifestation of the nonmelanocytic skin tumors are different. Ultraviolet radiation, infections with human papillomaviruses, and inherited or iatrogenic-induced immunosuppression (in cases of autoimmune diseases and organ transplant recipients) are considered to be some of the most important generators and/or costimulating factors supporting the appearance of "de-novo" mutations and obstruct, in one or another way, the cell cycle arrest, the programmed cell death (apoptosis), and the immunosurveillance. Preconditions are thus created for the initial persistence and subsequent proliferation of the malignant cell branch in the genome, with the simultaneous increase of the risk of nonmelanocytic skin tumor manifestation.A number of medical drugs that possess a currently well-known selective, targeting, and immunomodulating effect, like the TNF-alpha inhibitors for example, most probably possess an additional blocking action on the death receptors within the framework of the extrinsic apoptotic pathway. In this way, they seem to be one of the major factors for the clinical manifestation not only of nonmelanocytic skin but also of a number of other type of tumors with a dependency on the genetic predisposition of each separate patient.This article focuses the attention on the basic exogenic and endogenic factors that affect the regulatory processes of the cellular cycle, apoptosis, immunosurveillance, and the human inflammasome in patients with nonmelanocytic skin tumors. These processes are interwoven in a complex network and are controlled by (1) the genome regulator p53, (2) its interaction with the proapoptotic acting proteins Bak and Bax, (3) as well as the interaction with the key regulatory protein of the inflammasome-ASC/TMS1.As a process, the malignant transformation is exceptionally dynamic, plastic, and adaptive. The exterior "interferences", on the part of the clinician, in the form of a planned therapy should be targeted at the simultaneous impact on the various pathogenetic chains with the objective of bringing the tumor cells to their total collapse. This can be made possible only after the careful and simultaneous-or parallel-examination of a much greater number of markers that serve to characterize the process of the malignant transformation-a fact, which is currently being disregarded by many researchers.

Novel biomarkers and therapeutic targets for optimizing the therapeutic management of melanomas

Cutaneous malignant melanoma is the most aggressive form of skin cancer with an extremely poor survival rate for the patients diagnosed with locally invasive and metastatic disease states. Intensive research has led in last few years to an improvement of the early detection and curative treatment of primary cutaneous melanomas that are confined to the skin by tumor surgical resection. However, locally advanced and disseminated melanomas are generally resistant to conventional treatments, including ionizing radiation, systemic chemotherapy, immunotherapy and/or adjuvant stem cell-based therapies, and result in the death of patients. The rapid progression of primary melanomas to locally invasive and/or metastatic disease states remains a major obstacle for an early effective diagnosis and a curative therapeutic intervention for melanoma patients. Importantly, recent advances in the melanoma research have led to the identification of different gene products that are often implicated in the malignant transformation of melanocytic cells into melanoma cells, including melanoma stem/progenitor cells, during melanoma initiation and progression to locally advanced and metastatic disease states. The frequent deregulated genes products encompass the oncogenic B-RafV600E and N-RasQ61R mutants, different receptor tyrosine kinases and developmental pathways such as epidermal growth factor receptor (EGFR), stem cell-like factor (SCF) receptor KIT, hedgehog, Wnt/β-catenin, Notch, stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor-4 (CXCR4) and vascular endothelial growth factor (VEGF)/VEGFR receptor. These growth factors can cooperate to activate distinct tumorigenic downstream signaling elements and epithelial-mesenchymal transition (EMT)-associated molecules, including phosphatidylinositol 3’-kinase (PI3K)/Akt/ molecular target of rapamycin (mTOR), nuclear factor-kappaB (NF-κB), macrophage inhibitory cytokine-1 (MIC-1), vimentin, snail and twist. Of therapeutic relevance, these deregulated signal transduction components constitute new potential biomarkers and therapeutic targets of great clinical interest for improving the efficacy of current diagnostic and prognostic methods and management of patients diagnosed with locally advanced, metastatic and/or relapsed melanomas.

Immunohistochemical expression of p16, p21, p27 and cyclin D1 in oral nevi and melanoma

The acquisition of abnormalities at G1/S is considered a crucial step in the genesis and progression of melanoma. The expression of cell cycle regulators has also been used in various neoplasms as an adjunct to diagnosis. The aim of this study was to compare the expression of p16, p21, p27 and cyclin D1 in oral nevi and melanomas. Expression of these cell cycle regulatory proteins was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas. p16 and p27 were highly expressed in intramucosal nevi, whereas p21 and cyclin D1 expression was higher in oral melanomas. The results indicate that p21 and cyclin D1 may be involved in the development of oral melanomas, and eventually they may be useful in the differential diagnoses of oral benign and malignant melanocytic lesions.

Prognostic significance of cytoplasmic p27 expression in human melanoma

BACKGROUND

The cyclin-dependent kinase inhibitor p27 plays important roles in cell proliferation, cell motility, and apoptosis. Interestingly, the nuclear and cytoplasmic p27 exert opposite biological functions. In this study, we investigated the prognostic impact of subcellular p27 expression.

METHODS

We constructed melanoma tissue microarrays in a large series of melanoma patients, including 29 normal nevi, 52 dysplastic nevi, 270 primary melanomas, and 148 metastatic melanomas. The expression level of subcellular p27 in different stages of melanocytic lesions and its prognostic significance were evaluated.

RESULTS

Compared with dysplastic nevi, nuclear p27 expression was remarkably reduced in primary melanomas and further reduced in metastatic melanoma (P < 0.001 for both), whereas cytoplasmic p27 expression is significantly increased from dysplastic nevi to primary melanomas (P = 0.032) and further increased in melanoma metastases (P = 0.037). Although loss of nuclear p27 expression is correlated with a worse 5-year survival of primary melanoma patients in Kaplan-Meier analysis (P = 0.046), it is not a prognostic factor by multivariate Cox regression analysis. On the contrary, Kaplan-Meier analysis showed that gain of cytoplasmic p27 was associated with a poor 5-year survival of metastatic melanoma patients (P < 0.001). Multivariate Cox regression analysis revealed that positive cytoplasmic p27 expression is an independent prognostic factor to predict metastatic melanoma patient outcome.

CONCLUSION

Cytoplasmic p27 may serve as a promising prognostic marker for metastatic melanoma.

IMPACT

Because there is no reliable prognostic marker for metastatic melanoma, our finding may have important clinical implications using cytoplasmic p27 as a prognostic biomarker for advanced melanoma.

A novel biomarker harvesting nanotechnology identifies Bak as a candidate melanoma biomarker in serum

BACKGROUND

Melanoma represents only 4% of all skin cancers, but nearly 80% of skin cancer deaths. This manuscript applies several new measurement technologies with the purpose of elucidating molecular signatures of melanoma aggressiveness.

PURPOSE

We sought to determine whether low-abundant serum proteins related to apoptotic pathways could be measured and correlated with defined melanoma subtypes. Hydrogel core shell nanoparticles, a new technology capable of selectively entrapping low molecular weight proteins and protecting them from enzymatic degradation, were used to capture candidate serum biomarkers. Biomarker levels were correlated with confocal microscopy, thereby representing a combination of new technologies for in vivo histologic documentation.

RESULTS

Among a panel of analyzed serum proteins, Bak was differentially expressed between nevi and melanomas. Melanomas with higher Bak serum levels exhibited more pronounced junctional activity on confocal imaging, whereas lesions with 'sparse' dermal nests had weak Bak expression.

CONCLUSIONS

Our study links serum proteome analysis with confocal microscopic clinical in vivo histologic classification of melanomas. Bak has not been previously measured in serum. Bak differential expression among melanoma subtypes confirms the importance of the apoptotic pathway as a contributor to melanoma aggressiveness.

Tissue inhibitor of metalloproteinase-1 promotes NIH3T3 fibroblast proliferation by activating p-Akt and cell cycle progression

Tissue inhibitor of metalloproteinase-1 (TIMP-1) plays various roles in cell growth in different cell types. However, few studies have focused on TIMP-1's effect on fibroblast cells. In this study, we investigated the effects of TIMP-1 overexpression on NIH3T3 fibroblast proliferation and potential transduction signaling pathways involved. Overexpression of TIMP-1, by transfection of the pLenti6/V5-DESTTIMP-1 plasmid, significantly promoted NIH3T3 proliferation as determined by the BrdU array. Neither 5 nor 15 nM GM6001 (matrix metalloproteinase system inhibitor) affected NIH3T3 proliferation, but 45 nM GM6001 inhibited proliferation. TIMP-1 overexpression activated the p-Akt pathway, but not the p-ERK or p-p38 pathway. In TIMP-1-transfected cells, cyclinD1 was upregulated and p21CIP1 and p27(KIP1) were downregulated, which promoted cell entry into the S and G2/M phases. The PI3-K inhibitor LY294002 abolished the TIMP-1-induced effects. Overexpression of intracellular TIMP-1 stimulated NIH3T3 fibroblast proliferation in a matrix metalloproteinase (MMP)-independent manner by activating the p-Akt pathway and related cell cycle progression.

Born to be alive: a role for the BCL-2 family in melanoma tumor cell survival, apoptosis, and treatment

The global incidence of melanoma has dramatically increased during the recent decades, yet the advancement of primary and adjuvant therapies has not kept a similar pace. The development of melanoma is often centered on cellular signaling that hyper-activates survival pathways, while inducing a concomitant blockade to cell death. Aberrations in cell death signaling not only promote tumor survival and enhanced metastatic potential, but also create resistance to anti-tumor strategies. Chemotherapeutic agents target melanoma tumor cells by inducing a form of cell death called apoptosis, which is governed by the BCL-2 family of proteins. The BCL-2 family is comprised of anti-apoptotic proteins (e.g., BCL-2, BCL-xL, and MCL-1) and pro-apoptotic proteins (e.g., BAK, BAX, and BIM), and their coordinated regulation and function are essential for optimal responses to chemotherapeutics. Here we will discuss what is currently known about the mechanisms of BCL-2 family function with a focus on the signaling pathways that maintain melanoma tumor cell survival. Importantly, we will critically evaluate the literature regarding how chemotherapeutic strategies directly impact on BCL-2 family function and offer several suggestions for future regimens to target melanoma and enhance patient survival.

New advances on critical implications of tumor- and metastasis-initiating cells in cancer progression, treatment resistance and disease recurrence

Accumulating lines of experimental evidence have revealed that the malignant transformation of multipotent tissue-resident adult stem/progenitor cells into cancer stem/progenitor cells endowed with a high self-renewal capacity and aberrant multilineage differentiation potential may be at origin of the most types of human aggressive and recurrent cancers. Based on new cancer stem/progenitor cell concepts of carcinogenesis, it is suggested that a small subpopulation of highly tumorigenic and migrating cancer stem/progenitor cells, also designated as cancer- and metastasis-initiating cells, can provide critical roles for primary tumor growth, metastases at distant tissues and organs, treatment resistance and disease relapse. Particularly, cancer initiation and progression to locally invasive and metastatic stages is often associated with a persistent activation of distinct developmental signaling pathways in these immature cells during epithelial-mesenchymal transition program. The signaling cascades that are often deregulated in cancer stem/progenitor cells include hedgehog, epidermal growth factor receptor (EGFR), Wnt/beta-catenin, NOTCH, polycomb gene product BMI-1 and/or stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4). Importantly, the results from recent investigations have also indicated that different cancer subtypes may harbor distinct subsets and/or number of cancer-initiating cells during cancer progression as well as before or after therapy initiation and disease recurrence. Therefore, the identification of the molecular transforming events that frequently occur in cancer- and metastasis-initiating cells versus their differentiated progenies is of immense interest to develop new targeting approach for improving current therapies against aggressive, metastatic, recurrent and lethal cancers.

[Dissecting the pathways of tumour escape: " question of life and death?"]

Apoptotic pathways are providing important saveguard mechanisms in protection from cancer by eliminating altered and often harmful cells. The disturbances of cell proliferation, differentiation and apoptosis are also found on specific signal-transduction pathways within the tumour cells and between these and the immune system. The article focuses attention on the evolution of the melanocytic naevi in the direction of a dysplastic or tumour cell. The determination of single molecules as prognostic parameters within cancer genesis seems to be problematic. New hopes are being placed on the treatment with TW-37, ABT-737 and TAT-Bim, which, to an extent, are able to support the programmed cell death. The clinical importance of these innovative therapies remains to be seen and should therefore, be viewed with considerable criticism.

Recent advances on skin-resident stem/progenitor cell functions in skin regeneration, aging and cancers and novel anti-aging and cancer therapies

Recent advances in skin-resident adult stem/progenitor cell research have revealed that these immature and regenerative cells with a high longevity provide critical functions in maintaining skin homeostasis and repair after severe injuries along the lifespan of individuals. The establishment of the functional properties of distinct adult stem/progenitor cells found in skin epidermis and hair follicles and extrinsic signals from their niches, which are deregulated during their aging and malignant transformation, has significantly improved our understanding on the etiopathogenesis of diverse human skin disorders and cancers. Particularly, enhanced ultraviolet radiation exposure, inflammation and oxidative stress and telomere attrition during chronological aging may induce severe DNA damages and genomic instability in the skin-resident stem/progenitor cells and their progenies. These molecular events may result in the alterations in key signalling components controlling their self-renewal and/or regenerative capacities as well as the activation of tumour suppressor gene products that trigger their growth arrest and senescence or apoptotic death. The progressive decline in the regenerative functions and/or number of skin-resident adult stem/progenitor cells may cause diverse skin diseases with advancing age. Moreover, the photoaging, telomerase re-activation and occurrence of different oncogenic events in skin-resident adult stem/progenitor cells may also culminate in their malignant transformation into cancer stem/progenitor cells and skin cancer initiation and progression. Therefore, the anti-inflammatory and anti-oxidant treatments and stem cell-replacement and gene therapies as well as the molecular targeting of their malignant counterpart, skin cancer-initiating cells offer great promise to treat diverse skin disorders and cancers.

Reduced p16 and increased cyclin D1 and pRb expression are correlated with progression in cutaneous melanocytic tumors

The immunohistochemical expression of cell cycle proteins p16, cyclin D1, and pRb was assessed in 112 benign and malignant melanocytic tumors and correlated with tumor progression, prognosis, and outcome. Comparing benign and malignant tumors, there were significant differences in the median score for all 3 proteins, with decreased p16 (P = .000001), increased cyclin D1 (P = .01), and increased pRb in melanomas (P = .01). There was a progressive loss of expression of p16 with progression from benign naevi to primary melanomas and to metastases. p16 was significantly decreased in primary tumors from melanoma patients who developed recurrent disease (P = .0000013). Cyclin D1 and pRb showed a progressive increase in expression from benign to malignant tumors but with relative decreases in the more advanced tumors (thick primaries and metastatic melanomas). Alterations in cell cycle proteins involved in G1/S transition are implicated in melanocytic tumor progression and have a potential role in diagnosis and prognostication.

Suberythemal ultraviolet B radiation alters the expression of cell cycle-related proteins in the epidermis of human subjects without leading to photoprotection

BACKGROUND

Deregulation of the cell cycle proteins is one of the critical factors leading to cutaneous carcinogenesis.

OBJECTIVES

To monitor the expression of cell cycle proteins in the epidermis of subjects after repeated exposure to ultraviolet (UV) B radiation, and to test for the development of photoprotection by subsequent irradiation with a single erythemal UVB dose.

METHODS

A total of 26 healthy volunteers were divided into four groups: group 1 (n = 9) were given whole-body UVB irradiation for 10 consecutive days with 0.7 minimal erythema dose (MED), group 2 (n = 9) were irradiated as in group 1 followed 24 h later by a single UVB dose of 3 MED on buttock skin, group 3 (n = 4) were irradiated with a UVB dose of 3 MED on buttock skin, and group 4 (n = 4) were not irradiated. Skin biopsies were collected 24 h after the final irradiation and stained for cyclins A, B1, D1, and p16, p18, p21, p27, p53, pRB, Bax and Bcl-2.

RESULTS

The expression of cyclin D1, p18 and p21 was significantly higher in groups 1 and 2 compared with the nonirradiated group 4 controls and, in group 2, the expression of pRB, p53 and Bax was also increased. In group 3, only p53 and Bax proteins were significantly elevated compared with group 4. The expression of cyclin D1, p16, p18, p27, pRB and Bcl-2 was higher in group 2 compared with group 3.

CONCLUSIONS

Suberythemal UVB radiation was sufficient to cause changes in the expression of several epidermal cell cycle proteins. When tested by irradiation with a single erythemal UVB dose following the repeated exposures, no photoprotection against the UV-induced alteration in cell cycle protein expression was apparent.

Effect of p27mt gene on apoptosis of the colorectal cancer cell line Lovo

AIM: To construct p27mt recombinant adenovirus, transfect the colorectal cell line Lovo and observe the effects of p27mt on Lovo cell apoptosis and cell cycle inhibition.

METHODS: We constructed recombinant adenovirus containing p27mt by homologous recombination in bacteria. The colorectal cancer cell line Lovo was infected with recombinant replication-defective adenovirus Ad-p27mt, and expression of p27mt was determined by Western blotting; the inhibitory effect of p27mt on Lovo cells was detected by cytometry. Cell cycle was determined by flow cytometry. DNA fragment analysis identified the occurrence of apoptosis.

RESULTS: The recombinant adenovirus which already contained p27mt target gene was successfully constructed. When multiplicity of infection was ≥ 50, the infection efficiency was 100%. After transfection of Lovo cells with Ad-p27mt the cells had high p27 expression which was identified by immunoblotting assay. PI staining and flow cytometry showed that 77.96% of colorectal cancer cells were inhibited in phase G₀/G₁, while in the Ad-LacZ group and blank control group, 27.57% and 25.29% cells were inhibited in the same phase, respectively. DNA fragment analysis, flow cytometry and TUNEL assay demonstrated that p27mt is able to induce apoptosis in colorectal cancer cells.

CONCLUSION: p27mt has an obvious blocking effect on colorectal cancer cell cycle, and most cells were inhibited in phase G₀/G₁. Therefore, p27mt can induce apoptosis in colorectal cells.

Molecular pathogenesis of cutaneous melanocytic neoplasms

Melanoma is the deadliest form of skin cancer without an effective treatment. An understanding of the genetic basis of melanoma has recently shed light on some of the mechanisms of melanomagenesis. This review explores the major genes involved in familial and sporadic cutaneous melanoma with an emphasis on CDKN2A, CDK4, MC1R, and MAPK pathway targets (e.g., RAS and BRAF), apoptosis regulators (e.g., BCL-2, AKT, and APAF-1), and the tumor-suppressor genes TP53 and PTEN. New directions for therapeutics based on our current knowledge of the genes implicated in melanoma are also discussed.

Recent insights into the molecular mechanisms involved in aging and the malignant transformation of adult stem/progenitor cells and their therapeutic implications

Recent advancements in tissue-resident adult stem/progenitor cell research have revealed that enhanced telomere attrition, oxidative stress, ultraviolet radiation exposure and oncogenic events leading to severe DNA damages and genomic instability may occur in these immature and regenerative cells during chronological aging. Particularly, the alterations in key signaling components controlling their self-renewal capacity and an up-regulation of tumor suppressor gene products such as p16(INK4A), p19(ARF), ataxia-telangiectasia mutated (ATM) kinase, p53 and/or the forkhead box O (FOXOs) family of transcription factors may result in their dysfunctions, growth arrest and senescence or apoptotic death during the aging process. These molecular events may culminate in a progressive decline in the regenerative functions and the number of tissue-resident adult stem/progenitor cells, and age-related disease development. Conversely, the telomerase re-activation and accumulation of numerous genetic and/or epigenetic alterations in adult stem/progenitor cells with advancing age may result in their immortalization and malignant transformation into highly leukemic or tumorigenic cancer-initiating cells and cancer initiation. Therefore, the cell-replacement and gene therapies and molecular targeting of aged and dysfunctional adult stem/progenitor cells including their malignant counterpart, cancer-initiating cells, hold great promise for treating and even curing diverse devastating human diseases. These diseases include premature aging diseases, hematopoietic, cardiovascular, musculoskeletal, pulmonary, ocular, urogenital, neurodegenerative and skin disorders and aggressive and recurrent cancers.

Cyclin-dependent kinase inhibitor p27Kip1 controls growth and cell cycle progression in human uterine leiomyoma

The molecular mechanism of the cell-cycle machinery in uterine leiomyoma has not yet been fully elucidated. Among the various types of cell-cycle regulators, p27(Kip1) (p27) is considered to be a potent tumor suppressor. To provide further molecular basis for understanding the progression of uterine leiomyoma, our objective was to evaluate the expression level of p27 in normal myometrium and uterine leiomyoma tissue and its effect on cytogenic growth. Western blot analysis, real-time polymerase chain reaction (PCR) and immunohistochemical staining revealed that p27 protein and messenger RNA were down-regulated in uterine leiomyoma tissue and cultured cells compared to normal myometrium. Full-length human p27 cDNA was transferred using a replication-deficient recombinant adenoviral vector (Ad.p27) into uterine leiomyoma cells and evaluated the effect on cell proliferation. Transfection of Ad.p27 into uterine leiomyoma cells resulted in the induction of apoptosis, reduction in viability and proliferation of uterine leiomyoma cells. Our results suggest a new paradigm that down-regulated p27 protein expression is the possible underlying mechanism for the growth of uterine leiomyoma and over-expression of p27 induces cell death. This study provides better understanding of the control exerted by p27 in regulating growth and disease progression of uterine leiomyoma.

Mebendazole induces apoptosis via Bcl-2 inactivation in chemoresistant melanoma cells

Most metastatic melanoma patients fail to respond to available therapy, underscoring the need for novel approaches to identify new effective treatments. In this study, we screened 2,000 compounds from the Spectrum Library at a concentration of 1 micromol/L using two chemoresistant melanoma cell lines (M-14 and SK-Mel-19) and a spontaneously immortalized, nontumorigenic melanocyte cell line (melan-a). We identified 10 compounds that inhibited the growth of the melanoma cells yet were largely nontoxic to melanocytes. Strikingly, 4 of the 10 compounds (mebendazole, albendazole, fenbendazole, and oxybendazole) are benzimidazoles, a class of structurally related, tubulin-disrupting drugs. Mebendazole was prioritized to further characterize its mechanism of melanoma growth inhibition based on its favorable pharmacokinetic profile. Our data reveal that mebendazole inhibits melanoma growth with an average IC(50) of 0.32 micromol/L and preferentially induces apoptosis in melanoma cells compared with melanocytes. The intrinsic apoptotic response is mediated through phosphorylation of Bcl-2, which occurs rapidly after treatment with mebendazole in melanoma cells but not in melanocytes. Phosphorylation of Bcl-2 in melanoma cells prevents its interaction with proapoptotic Bax, thereby promoting apoptosis. We further show that mebendazole-resistant melanocytes can be sensitized through reduction of Bcl-2 protein levels, showing the essential role of Bcl-2 in the cellular response to mebendazole-mediated tubulin disruption. Our results suggest that this screening approach is useful for identifying agents that show promise in the treatment of even chemoresistant melanoma and identifies mebendazole as a potent, melanoma-specific cytotoxic agent.

The promyelocytic leukemia zinc finger-microRNA-221/-222 pathway controls melanoma progression through multiple oncogenic mechanisms

The incidence of cutaneous melanoma is steadily increasing. Although several molecular abnormalities have been associated with melanoma progression, the mechanisms underlying the differential gene expression are still largely unknown and targeted therapies are not yet available. Noncoding small RNAs, termed microRNAs (miR), have been recently reported to play important roles in major cellular processes, including those involved in cancer development and progression. We have identified the promyelocytic leukemia zinc finger (PLZF) transcription factor as a repressor of miR-221 and miR-222 by direct binding to their putative regulatory region. Specifically, PLZF silencing in melanomas unblocks miR-221 and miR-222, which in turn controls the progression of the neoplasia through down-modulation of p27Kip1/CDKN1B and c-KIT receptor, leading to enhanced proliferation and differentiation blockade of the melanoma cells, respectively. In vitro and in vivo functional studies, including the use of antisense "antagomir" oligonucleotides, confirmed the key role of miR-221/-222 in regulating the progression of human melanoma; this suggests that targeted therapies suppressing miR-221/-222 may prove beneficial in advanced melanoma.