Expression of lamins depends on epidermal differentiation and transformation

BACKGROUND: It has been suggested that A- and B-type lamins, proteins of the nuclear lamina, play important roles in the morphogenesis of the nucleus and cellular differentiation. OBJECTIVE: To investigate the expression of these nuclear proteins in normal skin and some keratinocytic tumours of the skin. METHODS: We examined by means of immunohistochemistry the expression of lamins in normal skin and some keratinocytic tumours of the skin, such as squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Bowen's disease, solar keratosis, keratoacanthoma and seborrhoeic keratosis. RESULTS: In normal skin, A-type lamin was expressed in all epidermal cells, but the expression level of B-type lamins diminished from basal cells to granular cells. In keratinocytic tumours, the expression of A-type lamin was reduced, especially in BCCs, Bowen's disease and poorly differentiated SCCs. B-type lamins were reduced and exhibited heterogeneous expression patterns in most well-differentiated SCCs and keratoacanthomas. Antibodies against B-type lamins stained only peripheral cells of the lobules in keratoacanthomas, while no regular staining patterns were seen in well-differentiated SCCs. CONCLUSIONS: Lamin expression depends on the differentiation and transformation of the human skin. This finding should be useful for the diagnosis of keratinocytic tumours.     

Bax expression and growth behavior of basal cell carcinomas

BACKGROUND: To understand the typical growth behavior of basal cell carcinoma (BCC) we searched for the correlation between proliferation and apoptosis and progression of BCC. METHODS: Expression of Bcl-2, Bax, and Ki-67 was immunohistochemically investigated in both normal skin and BCC cells, as well as in the epidermis overlying BCC. RESULTS: The results showed that in normal epidermis, Bcl-2 was homogeneously expressed in the basal cell compartment, whereas Ki-67 expression was largely restricted to the parabasal layer, the layer just above the basal cell layer, and exhibited a more scattered staining pattern. Bax was occasionally expressed in the basal layer and widely in the suprabasal compartment. Strikingly, the apparently normal epidermis overlying BCC showed an increased Bd-2 staining. In BCC, cells stained homogeneously for Bcl-2, whereas Bax and Ki-67 showed scattered staining patterns. Simultaneous expression was seen for Bcl-2 and Bax in 80 +/- 7% of the tumor cells, and co-expression of Bcl-2 and Ki-67 in 20 +/- 7% of the tumor cells. The cells expressing Bcl-2 and Ki-67, but lacking expression of Bax, the progressive fraction, comprised on average 7 +/- 3% of the tumor cell population. CONCLUSION: These results suggest that this small progressive fraction of tumor cells, in combination with the relatively high percentage of cells still prone to apoptosis, can explain the indolent growth behavior of BCC.     

Expression of RPE65, a putative receptor for plasma retinol-binding protein, in nonmelanocytic skin tumours

BACKGROUND: In a recent report we described RPE65, a protein originally characterized in retinal pigment epithelium, to be expressed in normal human epidermis. RPE65 is suspected to be involved in cellular uptake of retinol which is transported in the bloodstream complexed with plasma retinol-binding protein. OBJECTIVES: To evaluate protein and mRNA expression of RPE65 in actinic keratosis (AK), squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) compared with normal skin. METHODS: RPE65 mRNA expression in skin tumours relative to normal skin of the respective donor was studied by real-time polymerase chain reaction in AK (n = 15), invasive SCC (n = 30) and BCC (n = 18). A peptide-specific anti-RPE65 antibody was used for immunohistochemical staining of formalin-fixed and paraffin-embedded tissue sections of the respective tumours. RESULTS: RPE65 mRNA expression was reduced in AK. A highly significant reduction of RPE65 mRNA was observed in invasive SCC relative to normal skin of the respective donors. Immunohistochemistry revealed a continuous staining of basal and suprabasal keratinocytes in normal human epidermis. RPE65 in AK shown by immunohistochemical staining was reduced and quite irregular, whereas invasive SCC revealed no staining of tumour cells with the anti-RPE65 antibody. RPE65 mRNA values were elevated, whereas immunohistochemical staining for RPE65 protein was heterogeneous in BCC. CONCLUSIONS: These results suggest progressive downregulation of RPE65 from AK to invasive SCC.     

SGK1在日光性角化病、基底细胞癌及鳞状细胞癌中的表达

目的：检测SGK1在日光性角化病（AK）、基底细胞癌（BCC）及鳞状细胞癌（SCC）中的表达。方法：采用免疫组化SABC法检测SGK1在25例正常皮肤(NS)、25例AK、28例BCC、28例皮肤鳞状细胞癌标本中的表达。结果：NS、AK、BCC和SCC标本中,SGK1阳性细胞率分别为（40.03±14.42）%,（36.63±14.28）%,（52.82±18.73）%和（52.58±20.13）%。BCC组和SCC组分别与NS组比较,差异均有统计学意义（Ps<0.05）。各组SGK1染色阳性细胞率>50%的标本分别为6例（24%）,3例（12%）,16例（57.14%）和14例（50%）,BCC组和SCC组分别与NS组比较,差异均有统计学意义（Ps<0.05）。结论：SGK1的高表达可能与基底细胞癌及鳞状细胞癌的发病有关。     

Hyaluronan,CD44 and versican in epidermal keratinocyte tumours

BACKGROUND: The high molecular weight polysaccharide hyaluronan is a major component of the extracellular matrix between the vital cells of human skin epidermis. The levels of hyaluronan, and those of the hyaluronan receptor CD44 and the hyaluronan binding proteoglycan versican, correlate with the aggressiveness of different human carcinomas of epithelial origin. OBJECTIVES: To study skin keratinocyte tumours for the expression of hyaluronan, the hyaluronan receptor CD44 and the hyaluronan binding proteoglycan versican. METHODS: Paraffin-embedded sections of 114 basal cell carcinomas (BCC), 31 in situ carcinomas (ISC) and 35 squamous cell carcinomas (SCC) were stained with a hyaluronan specific probe, biotinylated hyaluronan binding complex, and with monoclonal antibodies against CD44 and versican. RESULTS: Compared with normal epidermis, ISC and well differentiated SCCs showed an enhanced hyaluronan signal on carcinoma cells while CD44 expression level resembled that of normal skin. Less differentiated SCCs showed reduced and irregular expression of both hyaluronan and CD44 on carcinoma cells. In BCCs, hyaluronan and CD44 signals were absent or very low on the surface of carcinoma cells. However, hyaluronan was frequently present on BCC cell nuclei, a feature completely absent in ISC, SCC and normal epidermis. An accumulation of hyaluronan in the connective tissue stroma around the tumour was more frequent in SCCs than BCCs. Versican staining was positive around hair follicles and dermal blood vessels of normal skin. Peritumoral versican signal was present in a part of the BCCs but not in other tumours. CONCLUSIONS: The completely different hyaluronan and CD44 expression patterns in BCC and SCC probably reflect the different origins of the tumours, with BCC an undifferentiated keratinocyte and SCC a keratinocyte at an early stage in the differentiation pathway. The difference in hyaluronan and CD44 expression between these tumours may also contribute to the difference in their capacity to metastasize.     

p21 WAF1/cip1expression in non-melanoma skin tumors

Abnormal control of the cell cycle is closely linked to carcino-genesis. p21^WAF1/CIP1 protein is a universal inhibitor of Gl cyclin-dependent kinase and is induced by p53-dependent and -independent pathways. In order to elucidate the role of p21^WAF1/CIP1 in human skin carcinogenesis, protein expression in squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Bowen's disease (BD), actinic keratosis (AK), keratoacanthoma (KA), seborrheic keratosis (SK), and normal skin was examined using an immunohistochemical method. In normal skin, a few positive cells were seen in some cases in the upper spinous layer of the epidermis; sebaceous glands also had positive cells. In cases of SK and KA, positive cells were found in the basal and suprabasal epidermal layers (proliferation pattern), and in cases of BD and AK, positive cells were seen mainly in the upper spinous layer (differentiation pattern). Cases of SCC had more positive cells and showed two staining patterns: proliferation, or mixed. Cases of BCC had no positive cells. p21^WAF1/CIP1 has some unidentified role in keratinocyte tumorigenesis, which may not be related directly to carcinogenesis.     

Expression of EGF receptor,involucrin, and cytokeratins in basal cell carcinomas and squamous cell,carcinomas of the skin

Summary The distribution of several markers of keratinocyte differentiation was studied in normal epidermis, basal cell carcinomas (BCCs), and squamous cell carcinomas (SCCs) using the immunoperoxidase technique on frozen sections of punch biopsy specimens. As markers a panel of chain-specific monoclonal antibodies (MoAbs) directed against cytokeratin (CK) 4, 8, 10, 13, 18, and 19, a polyclonal antiserum against involucrin, as well as a MoAb against the epidermal growth factor (EGF) receptor were used. In 15 out of 19 BCCs tested, expression of CK 8 was seen. Only a few individual cells in a limited number of BCCs showed positive staining for CK 4, 18, or 19. No expression of CK 10 was seen except for some foci of cell keratinization. Involucrin was not found in BCCs except for some squamous horn cysts. In all BCC cells expression of EGF receptor was found. In the suprabasal layers of normal epidermis from SCC patients, positive staining for CK 10 was seen. A few individual cells in a limited number of SCCs showed positive staining for CK 4, 8, or 18. Involucrin was expressed in the center of SCCs and in the upper layers of normal epidermis. Expression of EGF receptor was found in all SCC cells. These results demonstrate differences in cellular origin and differentiation between BCC and SCC.     

组织蛋白酶D在皮肤鳞状细胞癌、基底细胞癌和脂溢性角化病的组织表达及其意义

目的：观察组织蛋白酶D（cathepsinD，CD）在皮肤鳞状细胞癌（SCC）、基底细胞癌（BCC）、脂溢性角化病（SK）的组织表达，分析其表达差异及其意义。方法：用免疫组化SP染色法检测CD在15例SCC、15例BCC、14例SK及10例正常对照皮肤组织中的表达。结果：CD在正常皮肤组织表达为阴性．在SK、BCC、SCC瘤组织中表达依次升高，在SCC、SK之间表达有显著性差异（P〈0．05）；CD在SK、BCC、SCC间质细胞表达阳性率分别为85．7％、66，7％、33．3％。结论：CD的表达水平可能与SCC侵袭和转移有关。     

Cathepsin B and D expression in squamous cell carcinoma

To elucidate involvement ol protcinascs in malignancy of keratinocytes. expression ol catbepsin B, a cysteine proteinase. and catbepsin D. an aspartic proteinase. was ascertained in lormalin-lixed paraffin-embedded specimens of nortnal skin, squamous cell carcinoma (SCC). Bowen's disease, seborrboeic keratosis and basal cell carcinoma (BCC). Presence of procalbepsin B and an intermediate form of catbepsin D was coiilirmed by Westerti blolling and enzytne activity analysis. Cathepsin B stained more Intensely In SCC tumour cells tban in normal epidermis: staining patterns were diffuse, grantilar or botb. Diflusc and granular patterns (procatbcpsin B and mature enzyme, respectively) appeared in inner and outer parts of tumour islands, respectively. Five of 20 cases of Bowen's disease sbowed diffuse enhanced catbepsin B expression: 20 cases of seborrhoeic keratosis or BCC did not. Cathepsin D stained intensely in tumour cells of half the SCC cases. The staining manner and distribution of cathepsins B and D was similar in the cytoplasm of cancer cells. No enhanced staining of cathepsin I) was seen in any cases of Bowen's disease, seborrhoeic keratosis. or BCC. Coexistence and localization of active mature forms of cathepsins B and D suggests that cooperation between tbe two enzymes may play an important part in invasion of SCC.     

The expression of SnoN in normal human skin and cutaneous keratinous neoplasms

Background  SnoN is a member of the ski family of proto-oncogenes. It has been revealed that SnoN plays a role in the regulation of cell growth, vertebrate development, and tumorigenesis. This study investigated the expression and significance of SnoN protein in normal human skin and in the development of seborrheic keratosis (SK), basal cell carcinoma (BCC), and squamous cell carcinoma (SCC) of the skin.
Methods  Six frozen sections of normal human skin, three of SK (acanthotic type), six of BCC, six of intraepidermal SCC (actinic keratosis, AK), and six each of poorly and well-differentiated SCC were immunohistochemically stained with a polyclonal antibody against SnoN.
Results  In normal epidermis, strong positive staining was observed in the suprabasal layers, whereas the basal cell layer was entirely unstained. Expression was observed in tumor cells with a squamoid phenotype in SK, but not in BCC. In intraepidermal SCC, although a strong signal was seen in the well-differentiated keratinocytes of the superficial epidermal cell layers, no signal was seen in the poorly differentiated atypical cells situated in the lower epidermis. In invasive SCC, a few scattered cells were positive for SnoN in the well-differentiated sample, but much larger numbers of positive cells were observed in the poorly differentiated sample.
Conclusions  On the basis of our results, it is suggested that SnoN is involved in differentiation in normal skin and benign and nonmetastatic skin tumors, but plays a proto-oncogenic role in undifferentiated SCC.     

热休克蛋白10、60在皮肤鳞状细胞癌、基底细胞癌、日光性角化病中的表达

目的 探讨热休克蛋白（HSP）10、60在皮肤鳞状细胞癌（SCC）、基底细胞癌（BCC）和日光性角化病（AK）中的表达水平。方法 采用免疫组化EnVision两步法测定HSP10、60在皮肤SCC、BCC、AK中的阳性表达水平,并与正常组对照。结果 与对照组比较,HSP10组只有BCC组的阳性表达高于正常组（Z = 3.24,P < 0.01）,AK组（Z = 0.74,P > 0.05）和SCC组（Z = 0.52,P > 0.05）与对照组比较差异无统计学意义;HSP10组中AK与BCC,AK与SCC的差异有统计学意义（P < 0.05）,但SCC与BCC组间差异无统计学意义（P > 0.05）。HSP60组三组的阳性表达均高于正常组,其中AK（Z = -2.90,P < 0.01）、BCC（Z = -2.15,P < 0.05）、SCC（Z = -2.78,P < 0.01）;三组间两两比较结果为AK = SCC > BCC（P < 0.05）。结论 HSP60的高表达可能与鳞状细胞癌、日光性角化病的生物行为有关。     

Increased level of c-erbB-2/neu/HER-2 protein in cutaneous squamous cell carcinoma

Overexpression of c-erbB-2/neu/HER-2 oncoprotein, a receptor tyrosine kinase, has been demonstrated in a variety of human cancers. To elucidate the involvement of c-erbB-2 in human skin carcinogenesis, we examined expression of the protein in skin samples from five cases of keratoacanthoma (KA), 10 of actinic keratosis (AK), 24 of squamous cell carcinoma (SCC) and 10 of basal cell carcinoma (BCC) and five samples of normal epidermis, using an immunohistochemical method on formalin-fixed, paraffin-embedded sections. Expression of c-erbB-2 was also examined in cultured SCC cell lines, a premalignant cell line and in cultured normal keratinocytes. Normal epidermal cells showed no or very little c-erbB-2 protein, but the covering epidermal layer of some tumours showed a few strongly positive cells. Samples of KA and AK showed barely detectable c-erbB-2 protein in only a few cases. Twenty of the 24 cases of SCC had elevated expression of c-erbB-2 protein with a tendency to more positive cells in metastatic lesions. Five of the 10 cases of BCC stained for c-erbB-2 but more weakly than those of SCC, Reaction products of the positive cells were seen in the cytoplasm. All three cultured SCC cell lines stained for c-erbB-2 protein more strongly than the premalignant HaCaT or normal keratinocytes. Our results indicate the possible involvement of c-erB-2 overexpression in the malignant conversion of keratinocytes.     

皮肤基底细胞癌组织中桥粒芯糖蛋白1+2表达的研究

目的：探讨皮肤基底细胞癌中桥粒芯糖蛋白1 2的表达。方法：采用免疫组化染色方法检测桥粒芯糖蛋白1 2在24例皮肤基底细胞癌皮损中的表达情况，并以8份正常组织作对照。结果：桥粒芯糖蛋白1 2在正常皮肤表皮细胞间表达较强，而皮肤基底细胞癌组织中表达显著减弱或无表达。结论：桥粒芯糖蛋白1 2可能在皮肤基底细胞癌的发生中起一定作用。     

抗凋亡基因Bcl－2在皮肤角朊细胞肿瘤中的表达

Ｂｃｌ－２是一种原癌基因，它可阻断程序化细胞死亡（细胞凋亡），我们用免疫组化标记Ｂｃｌ－２在１２例基底细胞癌和１０例鳞状细胞癌，结果示正常皮肤基底层细胞呈阳性，基底层以上各层细胞阴性；所有基底细胞癌均呈阳性。提示Ｂｃｌ－２在基底细胞癌的发生、发展中可能起着重要作用。     

Immunohistochemical localization of proliferating cell nuclear antigen/cyclin in human skin

Summary Expression of proliferating cell nuclear antigen/cyclin (PCNA/cyclin) in skin tissue specimens and cultured keratinocytes was studied using a monospecific antibody, obtained from a patient with systemic lupus erythematosus, and a monoclonal antibody. Indirect immunofluorescent staining revealed that cultured keratinocytes obtained from human foreskins expressed PCNA/cyclin as variable nuclear patterns in 15–30% of the cells. In normal human skin tissue specimens, PCNA/cyclin was demonstrated in only a few basal cells. Interestingly, PCNA/cyclin was expressed strongly in almost all the cells of the lowest layer of the epidermis adjacent to squamous cell carcinomas, whereas the tumor aggregates themselves had no positive staining. In contrast, no such characteristic staining was demonstrated in specimens of basal cell carcinoma. The staining pattern of PCNA/cyclin was different from that of Ki-67 in the skin tissue specimens. Our results suggest that PCNA/cyclin could be a useful marker of cell proliferation.     

桥粒芯糖蛋白1在不同表皮肿瘤中表达的研究

目的：了解桥粒芯糖蛋白1与表皮肿瘤的病理及生物学行为之间的关系。方法：采用过氧化物酶标记的链霉卵白素免疫组织化学染色方法，检测了桥粒芯糖蛋白1(Dsgl)在鳞状细胞癌、基底细胞癌、Bowen病、日光角化病、角化棘皮瘤、脂溢性角化病及正常皮肤中的表达。结果：Dsgl在正常表皮中显著表达；在鳞状细胞癌和基底细胞癌的肿瘤组织中表达显著减弱或消失；在Bowen病和日光角化病细胞间变区域无表达；在绝大多数角化棘皮瘤、脂溢性角化病中的表达为强而连续的胞膜染色，与正常表皮中的表达相似。结论：皮肤恶性肿瘤中Dsgl的表达显著减弱或消失，可能与肿瘤的侵袭性和转移有关，Dsgl可能对表皮良、恶性肿瘤的鉴别诊断具有一定价值。     

Foxpl及Ki-67在皮肤基底细胞癌的表达

目的：检测皮肤基底细胞癌（BCC）组织中Foxpl和Ki一67蛋白的表达。方法：采用免疫组化方法检测BCC组织石蜡切片中Foxpl和Ki-67蛋白的表达。结果：40例BCC标本中Foxpl蛋白的表达率为82．5％,Ki-67蛋白的表达率为75％,均显著高于对照组（均P〈O．01）。结论：Foxpl和Ki-67可能参与BCC的发生和发展。     

Anti-cytokeratin 20 staining of Merkel cells helps differentiate basaloid proliferations overlying dermatofibromas from basal cell carcinoma

Background: Basaloid epidermal proliferations (BEP), morphologically resembling basal cell carcinoma (BCC), have been described overlying dermatofibromas. Distinguishing the two is important because of non-aggressiveness of BEP and local aggressiveness of BCC. The aim of this study is to determine whether CK20 antibody staining for Merkel cells can be used as an adjunct method to differentiate BEP from BCC. Methods: Ten cases of BEP overlying dermatofibromas were selected. Ten cases of BCC were used as control. The two groups were stained with CK20 antibody. Numerical density of CK20 stained Merkel cells in peri-lesional epidermis, BEP and BCC was determined by examining 300 cells at 400X in two separate areas by three independent pathologists. To determine statistical significance, the results were compared using t-test method. Results: Density of Merkel cells in peri-lesional epidermis was 0.2-0.3%. No merkel cells were detected in the BCC. BEP overlying dermatofibromas showed an obvious increase in CK 20 stained Merkel cells. The difference was statistically significant (P < 0.02) Conclusions: We report a significant increase in CK20 stained Merkel cells in BEP overlying dermatofibromas as compared to BCC. CK20 antibody staining for Merkel cells can be used as an adjunct method to differentiate BEP overlying dermatofibromas from BCC. Mahmoodi M, Asad H, Salim S, Kantor G, Minimo C. Anti-CK20 staining of Merkel cells helps differentiate basaloid proliferations overlying dermatofibromas from basal cell carcinoma.     

Expression of bcl-2, p53 and Ki-67 in arsenical skin cancers

To investigate the regulation of apoptosis and proliferation in arsenic-induced skin cancers, we examined the expression of bcl-2. p53, and Ki-67 using immunohistochemical staining. Thirty patients with Bowen's disease (BD), ten with basal cell carcinoma (BCC), eight with squamous cell carcinoma (SCC) and eleven of perilesional normal skin (PLN) of the non-sun exposure sites from endemic area were examined. The results showed that: 1) bcl-2 was expressed in all of the BCC homogeneously, in none of the SCC, and in 12/30 of the BD focally or homogeneously; 2) p53 was expressed in all of the arsenical skin cancers with a labelling index of 75±14% of BD, 50±17% of BCC. 61±15% of SCC, and also in all of the perilesional normal skin with a labelling index of 55±24%; 3) Ki-67 was expressed in all of the skin cancers with labelling index of 58±17% of BD. 12±7% of BCC, 47±21% of SCC, and in 9/11 of PLN with a labelling index of 41±24%. Expression of bcl-2 in BCC or BD is related to the phenotype of germinative basal cell. The constant expression of bcl-2 i early dysplastic cells of BD and the earliest expression of P53 in the basal cells of perilesional normal skin indicate that the initial step of arsenic-induced carcinogenesis is from the basal germinative cells. There is no mutual relationship between bcl-2, p53 or Ki-67 expression in any type of the arsenical skin cancers, but there is a positive correlation between p53 and Ki-67 expression identified in perilesional normal skin. BD had the highest labelling index of p53 and Ki-67.