Aberrant expression of Fas and FasL pro‐apoptotic proteins in basal cell and squamous cell carcinomas

Background. Fas and FasL are cell‐surface receptors involved in apoptosis. Aim. To investigate Fas and FasL expression levels in basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) to gain an insight into the mechanisms of Fas/FasL apoptosis and immune evasion in epidermal tumours. Methods. Real‐time PCR and streptavidin–biotin immunohistochemistry techniques were used to detect Fas and FasL expression in BCC, SCC and normal skin specimens. Results. Fas and FasL mRNA expression and immunostaining levels were lower in the 21 BCC specimens than in normal skin, whereas they were higher in the 15 SCC specimens than in normal skin. Conclusion. FasL immunostaining correlated with the capability of the tumour to invade and metastasize; the absent or weak immunostaining in the BCC specimens correlated with low capability, and the strong staining in the SCC specimens correlated with high capability.     

Proteinase-activated receptor-2 expression in basal and squamous cell carcinomas compared with normal skin

Proteinase-activated receptor-2 (PAR-2) is a transmembrane G-protein expressed in many normal tissues and overexpressed in several cancer cell lines. It contributes to metastasis, promotes epidermal growth factor receptor proliferation, angiogenesis and tumor progression in many carcinomas. The purpose of this study was to investigate the expression of PAR-2 in basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in comparison with that of normal skin.
Immunohistochemical (IHC) expression of PAR-2 was examined using paraffin-embedded sections from 30 BCCs, 30 SCCs and also 30 normal sun-exposed skin specimens. PAR-2 was expressed in all specimens of SCC and normal skin. In marked contrast, all BCC specimens had negative IHC staining. Given the important role of PAR-2 in angiogenesis and metastasis, our finding can explain the far less aggressive behavior of BCC as compared with SCC.     

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.     

P16 is overexpressed in cutaneous carcinomas located on sun-exposed areas

BACKGROUND: Recently, an increased expression of P16, a cell cycle regulatory tumor suppressor protein, has been demonstrated in cervical squamous neoplasms as a marker of malignancy. In contrast, studies performed in skin carcinomas led to contradictory results. OBJECTIVES: Our first aim was to evaluate P16 expression in different types of non-melanoma skin cancers compared with normal skin and benign tumors. The second aim was to evaluate the relationship between P16 expression and the location of skin tumors (i.e. exposed versus non exposed sites). Finally, we also studied Ki67 expression in skin carcinomas and control biopsies. METHODS: Skin biopsy specimens with typical histologic features of squamous cell carcinoma (SCC; n = 30), Bowen's disease (BD; n = 17), basal cell carcinoma (BCC; n = 10), seborrheic keratosis (SK; n = 10) and normal human skin (NHS; n = 9) were obtained from 76 patients seen at our institution between 2001 and 2003. In all cases, P16 and Ki67 expression were evaluated by immunohistochemistry and image analysis. RESULTS: P16 overexpression was observed in 58% of cutaneous carcinomas (SCC: 60%; BD: 58%; BCC: 50%) versus 0% of SK or NHS (0%) (p = 0.006). Ki67 expression in over 5% of tumour cells was observed in 69% of cutaneous carcinomas (SCC: 54%; BD: 76%; BCC: 80%) versus 16% in the group including SK (30%) and NHS (0%) (p = 0.04). Overexpression of P16 was associated with a high rate of Ki67 positive tumour cells in 23/57 malignant skin tumors (40%). Both P16 was associated and Ki-67 were negative in 7/57 cases (12%). Sixty-eight percent of tumors located on sun-exposed areas versus 23% of those located on non sun-exposed areas overexpressed P16 (p = 0.02). CONCLUSION: Our study demonstrated that the expression of P16 and Ki67 is associated with skin carcinomas. No difference was observed according to histological types of carcinomas, suggesting that P16 and Ki67 expression did not correlate with the degree of proliferation and malignancy. Within cutaneous carcinoma specimens, P16 overexpression was significantly associated with the location on sun-exposed areas, suggesting a possible induction of P16 overexpression by UV radiation.     

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.     

Expression of vascular endothelial growth factor in basal cell carcinoma and cutaneous squamous cell carcinoma of the head and neck

BACKGROUND: Basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) can both arise from any cutaneous epithelial surface. BCC are slow growing and rarely metastasise, whereas SCC are usually more aggressive. It is likely that the angiogenic process plays a key role in determining rate of growth and propensity for dissemination. Angiogenesis is a complex process requiring many factors and a pivotal group of proteins involved in this process is vascular endothelial growth factor (VEGF). METHODS: Immunohistochemical expression of VEGF was assessed in 44 cases of BCC and 41 cases of cutaneous SCC from the head and neck region. RESULTS: VEGF was expressed by blood vessel endothelial cells in both adjacent skin and tumour, and in the basal keratinocyte layer of epidermis. In BCC, VEGF was expressed by tumour epithelial cells, predominantly at the invasive tumour front, in 24/44 cases and its expression was significantly greater than in adjacent skin (p = 0.038). More widespread VEGF expression was found in 32/41 cases of SCC, and it was significantly associated with the degree of tumour differentiation (p < 0.001). CONCLUSIONS: The patterns of VEGF expression in BCC and SCC may help to explain the different behaviour that is usually seen with these tumours.     

CD44V6在表皮肿瘤及恶性黑素瘤的表达

目的　研究CD44V6在鳞状细胞癌、基底细胞癌和恶性黑素瘤的表达。方法　免疫组织化学对石蜡包埋组织标本进行检测。结果　 1 0例鳞状细胞癌CD44V6膜表达阳性 ,且随癌细胞分化程度降低CD44V6表达下调。 1 0例基底细胞癌和 8例恶性黑素瘤不表达CD44V6。结论　CD44V6的表达与皮肤肿瘤的类型有关     

Significance of PC cell-derived growth factor and cyclin D1 expression in cutaneous squamous cell carcinoma

Background. PC cell‐derived growth factor (PCDGF) is an autocrine growth factor originally purified from the highly tumorigenic teratoma PC cell line. It participates in tumorigenesis and tumour progression through upregulation of cyclin D1. To date, there has been no report on the role of PCDGF in skin cancer, to our knowledge. Aim. To investigate the expression of PCDGF and cyclin D1 in basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and seborrhoeic keratosis (SK), and their relationship with the clinicopathological parameters of SCC. Methods. Immunohistochemical expression of PCDGF and cyclin D1 was examined in 42 SCC, 30 BCC and 20 SK tissues. Results. PCDGF and cyclin D1 were overexpressed in SCC or BCC tissues compared with normal skin or SK, and their expressions were significantly higher in SCC than in BCC. Moreover, positive expression of PCDGF and cyclin D1 was significantly correlated with depth of invasion and metastasis of SCC. There was significant correlation between PCDGF and cyclin D1 expression in SCC. Conclusions. Expression of PCDGF and cyclin D1 plays an important role in the tumorigenesis of BCC and SCC. Abnormal expression of PCDGF and Cyclin D1 may be related to invasion and metastasis of SCC.     

Investigation of the corticotropin-releasing hormone-proopiomelanocortin axis in various skin tumours

BACKGROUND: Various types of external stress cause the skin and central neuroendocrine system to express corticotropin-releasing hormone (CRH)-proopiomelanocortin (POMC) axis-related hormones. However, the precise role of the CRH-POMC axis-related hormones in various skin tumours is unclear. OBJECTIVES: This study examined expression patterns of the CRH-POMC axis-related hormones in skin tumours. METHODS: The production of CRH, adrenocorticotropic hormone (ACTH) and alpha-melanocyte-stimulating hormone (alpha-MSH) in various tumour cell lines including HaCaT and primary keratinocytes was examined using an enzyme-linked immunosorbent assay. Immunohistochemical analysis of the skin tumours was also performed. RESULTS: CRH, ACTH and alpha-MSH were strongly expressed in malignant skin tumour cell lines such as G-361 and DX-3 (both malignant melanoma, MM). However, normal and haematological malignancy cell lines did not express the CRH-POMC axis-related hormones. Immunohistochemical analysis of the skin tumours showed that MM (80%), squamous cell carcinoma (SCC, 70%) and basal cell carcinoma (BCC, 10%) had strong immunoreactivity (++/+++) for CRH. Strong ACTH and alpha-MSH expression was observed in MM (70% and 50%, respectively), SCC (80% and 60%, respectively) and BCC (70% and 50%, respectively). CONCLUSIONS: We report that an increase in the level of the CRH-POMC axis-related hormones is associated with malignant skin tumours such as MM. These results highlight the importance of the CRH-POMC axis-related hormones in the malignant tendency of skin tumours.     

Cytokine mRNA expression in basal cell carcinoma

There is evidence that cytokines (CKs) play a significant role in the development and/or progression of skin cancer. The aim of the present study was to investigate the mRNA expression of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-8 in biopsy specimens of basal cell carcinoma (BCC), and to compare the results with the mRNA levels of non-lesional skin of BCC patients and healthy subjects. Skin samples were obtained from 22 patients with BCC (lesional, non-lesional) and 25 healthy subjects (controls). Routine histology and real-time RT-PCR was performed. Histological examination revealed 12 nodular BCCs and 10 superficial BCCs. The mRNA levels of CKs observed in healthy controls did not significantly (P > 0.05) differ from non-lesional CK levels of BCCs patients. However, IL-6 and IL-8 levels of lesional skin were significantly (P < 0.05) higher than the CK levels observed in non-lesional skin and controls, respectively. mRNA expression of IL-6 and IL-8 showed a significant positive correlation (r = 0.51; P < 0.05). There was no significant (P > 0.05) difference between lesional mRNA levels of TNF-α and those levels observed in non-lesional skin and controls. The mRNA expression of CKs found in nodular and superficial BCCs did not significantly differ (P > 0.05). BCC is associated with a significant increase of IL-6 and IL-8 expression. We have shown for the first time that upregulation of IL-6 mRNA significantly correlates with IL-8 overexpresssion. In accordance with previous studies our data suggest a role for IL-6 and IL-8 in the development and/or progression of BCC, since mRNA expression of both CKs are significantly increased in tumour tissue.     

Lamin expression in normal human skin,actinic keratosis,squamous cell carcinoma and basal cell carcinoma

BACKGROUND: Aberrant expression patterns of nuclear lamins have been described in various types of cancer depending on the subtype of cancer, its aggressiveness, proliferative capacity and degree of differentiation. In general, the expression of A-type lamins (lamins A and C) has been correlated with a non-proliferating, differentiated state of cells and tissues. OBJECTIVES: To establish and compare the expression patterns of lamins in normal human skin, actinic keratosis (AK), squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). METHODS: Expression patterns of the individual lamin subtypes were studied immunohistochemically. The proliferation capacity of the tumour cells was detected using a specific antibody to Ki-67, and was related to the A-type lamin expression patterns. RESULTS: In normal skin, lamin A was expressed in the suprabasal cell compartment of the epidermis, whereas the basal cells were mostly unstained. BCCs and SCCs stained positive in most cells, while the epidermis overlying BCC and SCC and the epidermis in AK stained homogeneously and strongly in the basal cells in addition to the suprabasal cells. Lamin C was expressed in some basal cells of normal epidermis while the suprabasal cells stained strongly positive. Both BCCs and SCCs stained strongly positive for lamin C, with the difference that in BCC the staining was predominantly present in nucleolar structures with occasional staining of the nuclear envelope. The epidermis overlying SCC showed strong positivity in the lamina of virtually all cells. The expression of lamin C in the basal cells of AK resembled the expression pattern seen in the epidermis overlying BCC, i.e. a nucleolar staining next to nuclear envelope staining. Lamin B1 and B2 were found in virtually all cells in normal epidermis, AK, BCC, SCC and the epidermis overlying cancer. The percentage of Ki-67-expressing cells was highest in BCC (45%), and gradually decreased via epidermis overlying BCC, AK, SCC, and epidermis overlying SCC, to normal skin (11%). Simultaneous expression of A-type lamins and Ki-67 occurred in approximately 50% of the proliferating (Ki-67 positive) cells in BCC and SCC. CONCLUSIONS: Significant changes occur in the expression patterns of A-type lamins in both premalignant and malignant lesions of the skin. The profound overlap of lamin A and Ki-67 staining patterns indicates that the proliferating tumour cells may obtain a certain degree of differentiation. Finally, lamin A expression in the basal cell layer of the apparently normal epidermis overlying BCC may suggest its involvement in the primary process.     

Survivin和COX-2在皮肤基底细胞癌和鳞状细胞癌组织中的表达及相关性

目的了解皮肤基底细胞癌和皮肤鳞状细胞癌中Survivin和COX-2的表达情况及两者的关系。方法采用免疫组化法检测10例正常对照组、23例基底细胞癌、18例鳞状细胞癌组织中Survivin和COX-2的表达情况。结果 Survivin蛋白在正常组织中不表达,基底细胞癌和鳞状细胞癌中Survivin蛋白的表达率分别为60.87%和66.67%。COX-2在正常组织中的表达率为10%,基底细胞癌和鳞状细胞癌中COX-2的表达率分别为65.22%和66.67%,且明显高于其在正常组织中的表达率。Survivin的表达和COX-2的表达呈显著正相关(P0.05)。结论 Survivin蛋白和COX-2在皮肤基底细胞癌和皮肤鳞状细胞癌中高表达,两者呈正相关。     

Livin和Caspase-3在皮肤基底细胞癌和皮肤鳞状细胞癌组织中的表达及相关性分析

目的了解皮肤基底细胞癌和皮肤鳞状细胞癌组织中Livin和Caspase-3的表达情况及二者的关系。方法采用免疫组化法检测25例基底细胞癌、18例鳞状细胞癌组织中Livin和Caspase-3的表达情况。结果①Livin蛋白在正常皮肤组织中不表达,基底细胞癌和鳞状细胞癌组织中Livin蛋白的阳性表达率分别为64.00%和72.22%。②Caspase-3在正常皮肤组织中表达,且明显高于基底细胞癌和鳞状细胞癌组织中Caspase-3的表达。③Caspase-3的表达与Livin的表达呈显著负相关。结论Livin在基底细胞癌和鳞状细胞癌组织中高表达,Caspase-3蛋白在基底细胞癌和鳞状细胞癌组织中低表达,且与Livn的表达呈负相关,提示二者可能共同参与基底细胞癌和鳞状细胞癌发病过程。     

Fas ligand is expressed in normal skin and in some cutaneous malignancies

Fas, a cell surface receptor and member of the tumour necrosis factor receptor superfamily, induces apoptosis upon oligomerization by its ligand (Fas ligand: FasL). Detailed studies have revealed that Fas is broadly expressed in normal human tissues, but relatively little is known about the range of cell types capable of expressing FasL. The aim of this study was to determine the in vivo patterns of expression of Fas and FasL in human skin tissues. Immunohistochemistry was performed using paraffin-embedded samples of normal and neoplastic skin tissues. In normal skin, FasL was expressed in the epidermis, sebaceous glands, sweat glands and outer root sheath of the hair. In squamous cell carcinomas (SCC), all cases analysed expressed FasL at high levels, whereas 60% of basal cell carcinomas (BCC) were positive for FasL. Expression of Fas in normal skin was observed in the basal and spinous layers of the epidermis, the outer root sheath of the hair, and the sebaceous glands. Expression of Fas was observed in all the SCC tested and none of the BCC tested. Expression of FasL by normal cells and tumour cells in skin tissue, demonstrated for the first time in the present study, may provide an important clue to understanding skin physiology, and immune evasion of skin tumours.     

环氧化酶-2在表皮肿瘤中的表达

目的 探讨环氧化酶-2在不同表皮肿瘤中的表达及意义。方法 选择鳞状细胞癌8例、基底细胞上皮瘤10例、Bowen病8例和脂溢性角化病12例,运用免疫组化方法观察肿瘤细胞中环氧化酶-2的表达。结果 与正常表皮相比,环氧化酶-2在鳞状细胞癌、Bowen病、基底细胞上皮瘤中的表达明显上调,尤其以鳞状细胞癌中的表达最强。而环氧化酶-2在脂溢性角化病中的表达与正常人皮肤的表达近似。结论 环氧化酶-2表达的上调可能在表皮肿瘤的发生发展中发挥一定作用。     

Viral DNA detection and RAS mutations in actinic keratosis and nonmelanoma skin cancers

Background Actinic keratosis (AK) is a well‐established precancerous skin lesion that has the potential to progress to squamous cell carcinoma (SCC). Basal cell carcinoma (BCC) is a locally aggressive slowly growing tumour that rarely metastasizes. A number of viruses have been proposed to play a role in the development of nonmelanoma skin cancers (NMSC), but the most plausible evidence to date suggests that cutaneous human papillomavirus (HPV) is the key instigating factor. Objectives To evaluate the prevalence of HPV, cytomegalovirus (CMV), herpes simplex virus (HSV) and Epstein–Barr virus (EBV) and investigate their relationship with the presence of RAS gene mutations in cutaneous lesions obtained from nonimmunosuppressed patients. Methods HPV, CMV, HSV and EBV detection was performed using polymerase chain reaction (PCR) in skin biopsies (26 AK, 12 SCC and 15 BCC samples) that were collected from immunocompetent patients. The RAS mutation incidence was also investigated in all cutaneous lesions by use of PCR/restriction fragment length polymorphism and direct DNA sequencing. Results Seventeen out of 53 (32%) skin lesions were found to be positive for HPV DNA. The highest incidences of HPV infection were five of 15 (33%) in BCC and four of 12 (33%) in SCC specimens. The HPV incidence was eight of 26 (31%) in AK and eight of 53 (15%) in normal skin tissue. Twelve out of 53 (23%) skin lesions were CMV‐positive. The highest incidence of CMV infection was six of 15 (40%), observed in BCC specimens. The CMV incidence was two of 26 (8%) in AK and four of 12 (33%) in SCC. No normal skin biopsy was found to be positive for CMV. All cutaneous samples were negative for HSV and EBV DNA, as assessed by our PCR‐based assays. Only three samples, one AK (4%), one BCC (6%) and one SCC (8%), were found to carry a G>T transversion at the second position of HRAS codon 12. Both HRAS mutant SCC and BCC biopsies were HPV‐ and CMV‐positive, as well. Conclusions HPV DNA is detected in NMSC, AK and normal skin biopsies. Our results also indicate that CMV is involved in NMSC at higher levels than in premalignant lesions, whereas the virus was not detected in normal skin biopsies. HSV and EBV do not appear to be involved in the pathogenesis of cutaneous lesions. Moreover, we suggest that the HRAS codon 12 mutation is not a very common event in AK or NMSC. Finally, both viral infection and HRAS activation appear to represent independent factors in the aetiology of NMSC, samples of which were obtained from immunocompetent patients.     

Differential expression of E prostanoid receptors in murine and human non-melanoma skin cancer

Enhanced prostaglandin production via upregulated cyclooxygenase-2 (COX-2) expression is a likely contributing factor in ultraviolet B (UVB)-induced non-melanoma skin cancer (NMSC), which consists primarily of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). The four E prostanoid (EP) receptors, designated EP1 through EP4, are known to bind prostaglandin E2 (PGE2), the major prostaglandin present in the skin. We used murine models of UVB-induced SCC and BCC, as well as human NMSC from sun-exposed sites, to investigate the expression of EP receptors during UVB-induced tumorigenesis. We observed that UVB-induced murine SCC are associated with markedly altered expression patterns of the EP receptors when compared with non-irradiated skin. In contrast, expression of all EP receptors was largely absent in UVB-induced murine BCC. We also observed expression of all four EP receptors in human SCC, with altered expression of their mRNA levels as compared with adjacent tumor-free skin. Consistent with our murine studies, no EP receptor expression was detected in human BCC, and their mRNA expression levels showed no change from the adjacent non-tumor-bearing skin. These data suggest that altered EP receptor expression may play a differential role in the development of UVB-induced SCC and BCC in murine and human skin.