Cyclin D1 and D3 expression in melanocytic skin lesions

Cyclins, cyclin-dependent kinases, as well as proteins cooperating with them are responsible for cell cycle regulation which is crucial for normal development, injury repair, and tumorigenesis. D-type cyclins regulate G1 cell cycle progression by enhancing the activities of cyclin-dependent kinases, and their expression is frequently altered in tumors. Disturbances in cyclin expression were also reported in melanocytic skin lesions. The objective of the study was to evaluate the expression of cyclins D1 and D3 in common, dysplastic, and malignant melanocytic skin lesions. Forty-eight melanocytic skin lesions including common nevi (10), dysplastic nevi (24), and melanomas (14) were diagnosed by dermoscopy and excised. Expression of cyclin D1 and D3 was detected by immunohistochemistry and quantified as percentage of immunostained cell nuclei in each sample. In normal skin, expression of cyclins D1 and D3 was not detected. The mean percentage of cyclin D1-positive nuclei was 7.75% for melanoma samples, 5% for dysplastic nevi samples, and 0.34% for common nevi samples. For cyclin D3, the respective values were 17.8, 6.4, and 1.8%. Statistically significant differences in cyclin D1 expression were observed between melanomas and common nevi as well as between dysplastic and common nevi (p = 0.0001), but not between melanomas and dysplastic nevi. Cyclin D3 expression revealed significant differences between all investigated lesion types (p = 0.0000). The mean cyclin D1 and D3 scores of melanomas with Breslow thickness <1 mm and >1 mm were not significantly different. G1/S abnormalities are crucial for the progression of malignant melanoma, and enhanced cyclin D1 and D3 expression leading to increased melanocyte proliferation is observed in both melanoma and dysplastic nevi. In histopathologically ambiguous cases, lower cyclin D3 expression in dysplastic nevi can be a diagnostic marker for that lesion type.     

β-连环蛋白和细胞周期蛋白D1在Bowen病中的表达

Bowen病是皮肤原位肿瘤,组织病理表现为表皮角化过度,伴有角化不全,棘层肥厚.表皮突延长增宽,肿瘤细胞位于表皮层,基底细胞层完整,表皮全层细胞排列紊乱,胞核有异形性,常见角化不良细胞、核分裂象及多核巨细胞.它的发生机制尚不清楚.     

Expression of cyclin D1 and p16 in psoriasis before and after phototherapy

Background. Psoriasis vulgaris (PV) is characterized by keratinocyte hyper‐proliferation. Altered expression of cell‐cycle regulatory genes involved in the cyclin D1/p16 INK4–pRb pathway may contribute to this epidermal hyperproliferation. Aim. To assess the expression of cyclinD1 and p16 in psoriasis, and to evaluate the effect of phototherapy on their expression. Methods. The study population comprised 25 patients with PV and 10 healthy controls. Patients were treated with 24 sessions of either narrowband ultraviolet (UV) B or psoralen UVA. Skin biopsies were taken from the affected skin of each patient before and after treatment, and from the healthy controls, to examine cyclin D1 and p16 expression. Results. Before phototherapy, the mean value of cyclin D1 concentration in patients was significantly greater than that in controls and the mean value of p16 concentration in patients was significantly lower than that in controls. Following treatment, we detected a significant decrease in cyclin D1 and a significant increase in p16. Conclusion. Cyclin D1 upregulation and p16 downregulation may play a role in the pathogenesis of psoriasis. Normalization of the levels of both parameters may be a mechanism by which phototherapy induces remission in psoriasis.     

Adhesion molecule expression in normal skin and melanocytic lesions

Cell adhesion between surfaces of cells and to extracellular matrices represents a fundamental mechanism in tissue organization and influences the biological behaviour and the architecture of tumors. We investigated the expression of various adhesion molecules in normal skin (n=5), nevi (n=29), and malignant melanoma (n=10) by immunohistochemistry. Special attention was paid to the correlation between adhesion molecule expression and the respective architectural features, e.g. UV-induced morphological changes, and the arrangement of melanocytes in congenital nevi. In nevi, a single erythemagenic close of UV-light did not influence the influence expression of melanocytes, but results in an upregulation of α3β1- and α6β1-integrin within the suprabasal layers of the epidermis. This suprabasal labelling was associated with an increased number of suprabasal melanocytes in UV-irradiated nevi which were detected with HMB-45 antibody. Nine of 10 congenital nevi demonstrated a labelling of α4β1-integrin only in melanocytes of the deeper dermis. This integrin previously has been associated with high tumor thickness and the clinical outcome in melanomas. The integrin profile observed in melanomas differed in part from that seen in nevi with expression of β2-and β3-integrins in some cases. The results may indicate a correlation between adhesion molecule expression and histopathological findings in melanocytic lesions.     

p16 expression in psoriatic lesions following therapy with propylthiouracil, an antithyroid thioureylene

Plaque formation is a characteristic finding in patients with psoriasis and reflects cytokine-induced keratinocyte proliferation and/or impaired apoptosis of keratinocytes. Antithyroid thioureylenes such as propylthiouracil (PTU) and methimazole (MMI) are effective in the treatment of plaque psoriasis. Following PTU and MMI treatment, proliferative cell nuclear antigen (PCNA) expression is significantly reduced, suggesting that these medications have an antiproliferative effect. p16 is an antiapoptotic protein that is present in relative abundance in psoriatic plaques and is believed to play a potential role in the persistent senescence and impaired apoptosis of the keratinocytes in the plaque. This study examined p16 expression in biopsy samples of eight patients with plaque psoriasis given 300 mg of propylthiouracil in divided doses for 3 months. Despite significant clinical and histological improvement with PTU treatment, p16 expression was essentially unchanged, suggesting that the beneficial effect of PTU in psoriasis is not mediated through a decrease in p16 expression. The effect of PTU on other antiapoptotic proteins such as bcl-xL remains to be determined.     

Cytoplasmic and nuclear expression of survivin in melanocytic skin lesions

Survivin, a member of the inhibitors of apoptosis protein family, regulates both cellular proliferation and apoptotic cell death. While the human survivin gene is highly expressed in the developing fetus, in adults its expression is restricted to highly proliferating normal tissues and neoplastic tumors tissues. In the present study, we compared the expression of survivin in melanoma and benign melanocytic lesions such as junctional, compound, dermal, congenital, blue and spitz nevi. This analysis reveals a heterogeneous expression of survivin with respect to both the intensity, frequency and cellular localization. In junctional, compound and blue nevi, survivin was present in nuclear localization, whereas in spitz nevi survivin was detectable in the cytoplasm. In dermal and congenital nevi, survivin was present in both localizations with predominance of the nuclear compartment. Interestingly, this distribution was similar to that observed in primary melanoma; whereas in metastatic melanoma the predominance of the nuclear localization of survivin was lost. Our data demonstrate that although survivin is expressed in a large number of benign nevi, the balance between its cytoplasmic and nuclear expression was immensely heterogeneous between lesions with suspected different developmental origins.     

P16、P21WAF1/CIP1、PCNA和cyclin E在脂溢性角化病中的表达及其意义

目的：研究脂溢性角化病皮损组织中P16、P21^WAF1/CIP1、PCNA、cyclinE四种细胞周期素相关因子的表达及意义。方法：应用免疫组化PV法（改进的SP法），对50例脂溢性角化病病人和10例正常人皮肤进行P16、P21^WAF1/CIP1、PCNA、cyclinE四种细胞周期素相关因子的测定。结果：脂溢性角化病患者中这四种因子的表达阳性率分别为：78％、68％、70％、46％；而正常对照组的阳性率仅为：40％、30％、50％、10％。结论：P16、P21^WAF1/CIP1、PCNA、cyclinE四种细胞周期素相关因子在脂溢性角化病的发病中可能起重要作用。     

Different expression patterns of p27 and p57 proteins in benign and malignant melanocytic neoplasms and in cultured human melanocytes

Background: The p27^KIP1 and p57^KIP2 proteins belong to the CIP/KIP family of cyclin‐dependent kinase inhibitors involved in the growth arrest and cellular senescence. High levels of p27^KIP1 unexpectedly have been detected in invasive malignant melanomas (MM), whereas the role of p57^KIP2 in melanocytic lesions is unknown. We therefore chose to study the expression of p27^KIP1 and p57^KIP2 in melanocytic neoplasms. Design: The expression of p27^KIP1 and p57^KIP2 were examined by immunohistochemistry in 40 melanocytic neoplasms and by Western blot analysis in cultured human melanocytes. Results: Expression of both nuclear p27^KIP1 and p57^KIP2 (> 10% of cells with nuclear labeling) was observed in most cases with non‐proliferating melanocytes (8/10, benign nevi and 9/10 DN, dysplastic nevi), but in only a few cases containing proliferating melanocytes (3/11 RN, recurrent nevi and 2/9 MM, melanoma) (p < 0.002). In proliferating melanocytes, there was an inverse correlation of nuclear expression of p27^KIP1 and p57^KIP2 in both RN (p27^KIP1 = 3/11 RN and p57^KIP2 = 8/11 RN) and MM (p27^KIP1 = 7/9 MM and p57^KIP2 = 2/9 MM) (p < 0.05). Western blot analysis detected p57^KIP2 only in proliferating melanocytes. p27^KIP1 was detected in both proliferating and senescent melanocytes. Conclusion: The difference in expression patterns of p27^KIP1 and p57^KIP2 in proliferating and senescent melanocytes suggests the interplay between these proteins may play a functional role in melanocytic tumorigenesis.     

Immunohistochemical expression of cyclooxygenage-2 in melanocytic skin lesions

Background Several reports have shown expression of cyclooxygenase‐2 (COX‐2) in malignant skin tumors. COX‐2 has also recently been reported as a marker of malignant melanoma (MM). Objective Our aim was to investigate whether there is a difference in the immunohistochemical expression of COX‐2 between malignant and benign melanocytic lesions of the skin. Methods We selected 40 archival cases of MM including 10 cases of superficial spreading melanoma, 10 of lentigo maligna melanoma, 10 of nodular melanoma, and 10 of acral lentiginous melanoma. For comparison, we also selected 35 benign melanocytic lesions, which included 15 nonatypical nevi and 10 atypical nevi. The remaining 10 cases were Spitz nevi. COX‐2 immunohistochemical staining was performed, and intensities were assessed quantitatively. Results The MM group and the benign melanocytic nevi group showed a highly statistically significant difference in the intensity of COX‐2 expression (P < 0.0001). Staining intensity in the dermal component of MM cases also showed a tendency to increase with increasing tumor depth. By contrast, the intensity of the dermal component in the melanocytic nevi group decreased with increasing depth as the nevus cells matured from type A to type C cells. No statistical difference was noted between the MM and Spitz nevi cases (P = 0.20). Conclusions Malignant melanoma shows stronger immunohistochemical expression of COX‐2 than benign melanocytic nevi. Although COX‐2 cannot be used alone to differentiate MM from melanocytic nevi, it may serve as an aid in the differential diagnosis of melanocytic skin lesions.     

Selective expression of FLIP in malignant melanocytic skin lesions

FLIP (FLICE Inhibitory Protein) is a recently identified intracellular inhibitor of caspase-8 activation that potently inhibits cell death mediated by all death receptors including Fas and TRAIL. FLIP has recently been shown to favor tumor growth and immune escape in mouse tumor models. We analyzed FLIP expression by immunohistochemistry in a panel of 61 benign and malignant human melanocytic skin lesions. FLIP expression was undetectable in all but one benign melanocytic lesion (31/32, 97%). In contrast, FLIP was strongly expressed in most melanomas (24/29 = 83%). Overexpression of FLIP by transfection in a Fas- and TRAIL-sensitive human melanoma cell line rendered this cell line more resistant to death mediated by both TRAIL and FasL. Selective expression of FLIP by human melanomas may confer in vivo resistance to FasL and TRAIL, thus representing an additional mechanism by which melanoma cells escape immune destruction.     

Induced expression of p16 and p21 proteins in UVB-irradiated human epidermis and cultured keratinocytes

It has been suggested that p16INK4a, the product of the cyclin-dependent kinase inhibitor 2 or multiple tumor suppressor 1 gene, prevents phosphorylation of the retinoblastoma gene product, and thus acts as a negative cell cycle regulator. To elucidate an effect of ultraviolet B (UVB) radiation on p16 expression and its relation to p21, and proliferating cell nuclear antigen (PCNA), immunohistochemical and western blot analyses were performed on UVB-irradiated normal human epidermis and cultured keratinocytes, respectively. Little p16 protein was seen in the control epidermis or keratinocytes. Increases in the levels of p16 protein in both UVB-irradiated epidermis and keratinocytes occurred in a similar manner, in which p16 was induced at 24-48 h and peaked at 72-120 h after irradiation. The induced expression of p21 was observed relatively earlier than that of p16, with peaked expression at 24-48 h and a return to control level by 168 h. PCNA expression was increased slightly until 48 h but significantly increased during 48-168 h of post-irradiation with peak expression at 72 h. These results indicate that together with p21, p16 protein may play an important role for protective or adaptive response to UVB exposure of human skin.     

AEG-1、P16、KI-67蛋白在宫颈癌前病变中的表达与临床意义

目的:探讨AEG-1、P16、KI-67蛋白在宫颈癌前病变中的表达与临床意义。方法:2008年2月至2015年9月选择在我院诊治的宫颈癌前病变患者98例作为癌前病变组,同期选择宫颈癌患者98例作为宫颈癌组和98例健康体检人作为对照组,取三组的宫颈样本都进行AEG-1、P16、KI-67蛋白表达的免疫组化分析,并调查了临床资料进行相关性分析。结果:AEG-1、P16、KI-67蛋白在宫颈癌组的阳性表达率分别为80.0%、93.9%和92.9%,而癌前病变组为57.1%、50.0%和57.1%,在对照组为3.1%、2.0%和4.1%,三组间对比差异有统计学意义(P0.05)。AEG-1、P16、KI-67蛋白的阳性表达与宫颈癌前病变的年龄、疾病类型、HPV感染等病理参数对比差异有统计学意义(P0.05)。直线相关性显示AEG-1、P16、KI-67蛋白表达都呈现两两正向相关性(P0.05)。结论:AEG-1、P16、KI-67蛋白在宫颈癌前病变中都呈现高表达状况,且与临床病理特征存在相关性,三者可互相作用影响宫颈癌前病变的发展状况。     

Significant melanocytic lesions in infancy, childhood, and adolescence

Malignant melanoma is diagnosed yearly in approximately 300 persons under age 20 in the United States. Relatively recent advances in dermatology include the recognition of lesions felt to be potential precursors of malignant melanoma. Small congenital melanocytic nevi, present in 1 per cent of all newborn infants, may have a small but definite potential for developing malignant melanoma. Furthermore, despite inconclusive data, many leading dermatologists now advocate removal of these small congenital lesions. Giant congenital melanocytic nevi, with their strong predilection for undergoing malignant change, are removed surgically at an early age, often in multistaged procedures. Dermabrasion, once felt to have a role in the treatment of giant congenital nevi, does not remove the malignant potential of these lesions. The dysplastic nevus syndrome, recognized in 1976, identifies individuals at increased risk for developing melanoma. Adolescents who have the dysplastic nevus syndrome or who are members of families with the syndrome require close medical supervision and patient education. The benign Spitz nevus, with its histologic similarity to malignant melanoma, continues to challenge the dermatopathologist and clinician. These lesions--the Spitz nevus, dysplastic nevus, congenital melanocytic nevus, and malignant melanoma--must all be actively considered when regarding the many other benign melanocytic lesions found in infancy, childhood, and adolescence.     

Skp2 and p27kip1 expression in melanocytic nevi and melanoma: an inverse relationship

BACKGROUND: S-phase kinase associated protein-2 (Skp2) ubiquitin ligase p45(SKP2) is important in the degradation of p27kip1 (a cyclin dependent kinase inhibitor) and progression through the G1-S cell-cycle checkpoint. Low levels of p27 and high levels of Skp2 are related to poor prognosis in some cancers. METHODS: Clinicopathologic features and immunohistochemical expression of Skp2 and p27kip1 were investigated in 198 melanocytic proliferations: 21 melanocytic nevi, 23 melanoma in situ, 119 primary melanoma, and 35 metastatic melanoma samples. Comparative and survival analyses were performed. RESULTS: Progressive and significant increases and decreases in the nuclear expression of Skp2 and p27kip1, respectively, was identified moving from melanocytic nevi (0.05 +/- 0.2/85 +/- 15) to melanoma in situ (3 +/- 2/45 +/- 20) to primary cutaneous melanoma (12 +/- 9/30 +/- 25) to metastatic melanoma (25 +/- 15/15 +/- 20) (p < or = 0.006). Expression of these proteins also significantly correlated with increasing American Joint Committee on Cancer (AJCC) T (tumor) classification and AJCC stage (p < or = 0.01). Moreover, the level of these two proteins exhibited a significant inverse relationship (r = -0.4, p = 0.0001). Skp2 cytoplasmic labeling index of >20% predicted worse 10-year overall survival (38% vs. 86%, p = 0.04) in primary melanoma. Neither p27 nor Skp2 nuclear expression impacted significantly on prognosis. CONCLUSIONS: Gain of Skp2 and loss of p27kip1 protein expression are implicated in melanoma progression where the level of p27kip1 may be regulated by targeted proteolysis via Skp2. Cytoplasmic expression of Skp2 defines a subset of aggressive melanomas and could represent another pathway of deregulation of the cell cycle.