Liren Tang

Aberrant Expression of Collagen Triple Helix Repeat Containing 1 in Human Solid Cancers

Purpose: The collagen triple helix repeat containing 1 (CTHRC1) is a promigratory protein first found to be expressed during rat tissue repair process. Recent preliminary results revealed CTHRC1 mRNA in melanoma and breast cancer. However, the full significance of CTHRC1 to human carcinogenesis remains unclear. This study is to further characterize the clinical and functional relevance of CTHRC1 in melanoma and other human solid cancers. Experimental Design: First, semiquantitative immunohistochemistry analysis was done on 304 clinically annotated, paraffin-embedded biopsies representing different stages of melanoma progression. Then, short interfering RNA was used to inhibit expression of CTHRC1 protein for migration analysis on cultured melanoma cells. Finally, the CTHRC1 expression was surveyed in 310 samples representing 19 types of human solid cancers. Results: In benign nevi and noninvasive melanoma biopsies, there was little CTHRC1 protein expression. In contrast, in invasive primary melanomas, there was a significant increase of CTHRC1 protein (P < 0.01, χ2 test). There was a further increase of CTHRC1 protein in metastatic melanoma specimens compared with nonmetastatic lesions (P < 0.01, χ2 test). In addition, inhibition of CTHRC1 expression resulted in decreased cell migration in vitro. Finally, transcription survey in 19 types of human solid cancers revealed aberrant CTHRC1 expression in 16 cancer types, especially cancers of the gastrointestinal tract, lung, breast, thyroid, ovarian, cervix, liver, and the pancreas. Conclusions: Aberrant expression of CTHRC1 is widely present in human solid cancers and seems to be associated with cancer tissue invasion and metastasis. It potentially plays important functional roles in cancer progression, perhaps by increasing cancer cell migration.

p53-regulated apoptosis is differentiation dependent in ultraviolet B-irradiated mouse keratinocytes.

Previous studies from our laboratory, using p53 transgenic mice, have suggested that ultraviolet (UV) light-induced keratinocyte apoptosis in the skin is not affected by overexpression of mutant p53 protein. To further elucidate a possible role for p53 in UV-induced keratinocyte cell death, we now examine apoptosis in skin and isolated keratinocytes from p53 null (-/-) mice and assess the influence of cell differentiation on this process. In vivo, using this knockout model, epidermal keratinocytes in p53-/- mice exhibited only a 5.2-fold increase in apoptosis after 2000 J/m2 UVB irradiation compared with a 26.3-fold increase in normal control animals. If this p53-dependent apoptosis is important in elimination of precancerous, UV-damaged keratinocytes, then it should be active in the undifferentiated cells of the epidermal basal layer. To test this hypothesis, we examined the effect of differentiation on UV-induced apoptosis in primary cultures of murine and human keratinocytes. Apoptosis was p53-independent in undifferentiated murine keratinocytes, which exhibited relative resistance to UVB-induced killing with only a 1.5-fold increase in apoptosis in p53+/+ cells and a 1.4-fold increase in p53-/- cells. Differentiated keratinocytes, in contrast, showed a 9.4-fold UVB induction of apoptosis in p53+/+ cells, almost three times the induction observed in p53-/- cells. This UV-induced difference in apoptosis was observed when keratinocytes were cultured on type IV collagen substrate, but not on plastic alone. Western blotting of UV-irradiated, differentiated keratinocytes did not support a role for either Bax or Bcl-2 in this process. In support of these findings in mice, cell death in human cultured keratinocytes also occurred in a differentiation-associated fashion. We conclude that p53-induced apoptosis eliminates damaged keratinocytes in the differentiated cell compartment, but this mechanism is not active in the basal, undifferentiated cells and is therefore of questionable significance in protection against skin cancer induction.

The expression of insulin-like growth factor 1 in follicular dermal papillae correlates with therapeutic efficacy of finasteride in androgenetic alopecia

BACKGROUNDnIt is generally believed that dihydrotestosterone is one of the pivotal mediators of hair loss in androgenetic alopecia (AGA). Finasteride, which blocks the conversion of testosterone to dihydrotestosterone, has now become an integral part of the current treatment approaches for male AGA. Several lines of evidence support the notion that dermal papilla (DP) cells represent the androgen target within the hair follicle. The specific molecular regulators modulated by androgens within hair follicles in the balding scalp are unknown.nnnOBJECTIVEnThe purpose of this study was to identify and quantify changes in expression of specific molecular hair growth regulators in DP of men with AGA treated with finasteride and correlate these findings to clinical efficacy.nnnMETHODSnBiopsy specimens were collected from 9 male patients from both the balding area and nonbalding occipital area before and after 4 months of finasteride therapy. DP were microdissected and total RNA was extracted from an equal number of DP from each biopsy specimen. The expression of various cytokines, including insulin-like growth factor (IGF)-1, was determined by reverse transcription polymerase chain reaction. The signals were detected by autoradiography. All 9 patients were given finasteride for 1 year and evaluated for efficacy at month 12. Efficacy was graded on a 7-point scale on the basis of comparison with initial baseline photography.nnnRESULTSnIGF-1 was up-regulated by finasteride treatment in 4 of 9 patients. Among the patients with increased IGF-1 expression, 3 of them showed moderate clinical improvement after 12 months of treatment and another patient remained unchanged. In contrast, 3 patients with decreased IGF-1 expression in the balding scalp showed clinical worsening after 12 months. The other 2 patients without noticeable change in IGF-1 expression showed either slight improvement or no change in their hair condition.nnnCONCLUSIONnIn a small uncontrolled study of 9 patients with AGA, an increased expression of IGF-1 messenger RNA levels in the DP was associated with patient response to finasteride.

Restoration of hair growth in mice with an alopecia areata-like disease using topical anthralin.

Abstract:u2002 Anthralin is a widely used topical anti‐psoriatic drug that may have an immunomodulating effect on alopecia areata (AA) as it does in psoriasis. The aims of the present study were to investigate the effects of anthralin on hair growth in balding C3H/HeJ mice affected by an AA‐like disease and to study the underlying mechanisms. Affected C3H/HeJ mice were treated daily for 10u2003weeks on half of the dorsal skin with 0.2% anthralin and the contra‐lateral side was treated with the vehicle ointment. The percentage of surface hair coverage and hair density was graded weekly for both sides and hair growth indices were calculated using these two variables. Hair regrowth was observed in 9/14 mice on the treated sides. Four mice displayed near complete replacement of normal density and length hairs. All the vehicle‐treated sides showed either no change or continued hair loss. An RNase protection assay (RPA) showed that expression of tumor necrosis factor‐α (TNF‐α) and ‐β were inhibited by anthralin upon successful treatment. It appears that anthralin may be an effective therapy for C3H/HeJ mice with AA and certain cytokines may be involved in the therapeutic effects of anthralin on restoring hair regrowth in AA‐affected C3H/HeJ mice.

Collagen Triple Helix Repeat Containing 1 Promotes Melanoma Cell Adhesion and Survival

Background: The extracellular protein collagen triple helix repeat containing 1 (CTHRC1) is aberrantly upregulated in melanoma and most human solid cancers. However, its role in cancer remains unknown. Objective: In this study, we investigated the functional impact of CTHRC1 on melanoma cells in vitro. Methods: Stable clones of cultured melanoma cells expressing different amounts of CTHRC1 protein were generated and evaluated to characterize their growth, survival, and attachment ability as well as their sensitivity to chemotherapy. Results: In cultured MMAN and MMRU melanoma cells, increased expression of CTHRC1 protein resulted in morphologic cell changes, enhanced cell adhesion to culture surfaces, increased cell proliferation, and decreased apoptosis. Furthermore, decreased CTHRC1 expression through antisense inhibition enhanced temozolomide sensitivity. Conclusion: CTHRC1 expression influences cellular processes, including cell adhesion and survival. Additionally, CTHRC1 inhibition may represent a potential method for decreasing melanoma resistance to conventional chemotherapy.

Efficacy and safety of topical WBI-1001 in the treatment of atopic dermatitis: results from a phase 2A, randomized, placebo-controlled clinical trial.

explain unique variance associated with sunbathing intentions and intentions to sun protect. For both analyses, age, sex, skin type, and perceived susceptibility were entered in step 1, followed by the 3 appearance-based tanning motives (appearance reasons to tan, appearance reasons not to tan, and sociocultural influences) entered in step 2. The overall R for both analyses was significant and indicated that a high level of variance was accounted for by the predictors (sunbathing R=.50; sun protection R=.62). In both regressions, appearance subscales of the PARTS explained significant variance beyond that explained by age, sex, skin type, and perceived susceptibility (Table). Appearance reasons to tan were significantly associated with sunbathing intentions (P .01) but not with sun protection intentions (P=.07): adolescents who positively endorsed appearance reasons to tan also reported more frequent intentions to sunbathe in the next 12 months and fewer intentions to sun protect. Appearance reasons not to tan were significantly associated with sunbathing intentions (P=.03) and with sun protection intentions (P .01): participants scoring higher on appearance reasons not to tan also reported fewer intentions to sunbathe and higher intentions to sun protect.

Topical nitrogen mustard in the treatment of alopecia areata: a bilateral comparison study.

Topical nitrogen mustard is an alkylating agent. Its efficacy in treating alopecia areata was reported in an uncontrolled study. We present a preliminary, half-head, controlled 16-week study showing that topical nitrogen mustard was of benefit in 1 of 6 patients treated with 50% to 100% scalp involvement. Another 4 patients did not complete the trial.

Endothelin-3 is produced by metastatic melanoma cells and promotes melanoma cell survival.

Background: Endothelin-3 (ET-3) is an essential paracrine factor for the proliferation, migration, and survival of embryonic melanocytes during fetal development. Its expression is tightly regulated, being completely turned off in adult skin. Objective: In this study, results are presented that demonstrate abnormal expression of ET-3 by metastatic melanoma cells in both tissue biopsies and cell culture. Further, in vitro experiments showed that metastatic melanoma cells have the capacity to respond to ET-3 stimulation by increasing survival. Conclusion: Therefore, an abnormal autocrine stimulation pathway involving ET-3 is present in metastatic melanoma cells. Blocking this signal transduction pathway may prove useful for the treatment of metastatic melanoma.

Restoration of hair growth with topical diphencyprone in mouse and rat models of alopecia areata

BACKGROUNDnThe contact sensitizer, diphencyprone (DPCP), is one of the most effective therapies for the more severe forms of alopecia areata (AA).nnnOBJECTIVEnThe purpose of this study was to determine the efficacy of topical DPCP on the 2 available rodent models for AA, and to determine the underlying therapeutic mechanisms.nnnMETHODSnAA-affected mice and rats were treated unilaterally with topical DPCP on the ventral and dorsal surface, respectively. The opposite sides were treated with vehicle alone. Skin biopsy specimens were collected from both sides for histologic analysis.nnnRESULTSnHair regrowth was observed on the treated sides in the majority of the animals of both species. Immunohistochemical analyses revealed reduction of intrafollicular CD8(+) lymphocyte infiltrates after successful treatment in mice.nnnCONCLUSIONnThe AA-like hair disorder of these 2 rodent models can be used as a tool for furthering our understanding of human AA and the therapeutic actions of DPCP.

Up-regulation of SERPINA3 correlates with high mortality of melanoma patients and increased migration and invasion of cancer cells

Serpin Peptidase Inhibitor, clade A member 3 (SERPINA3) was found to be abnormally overexpressed in a subset of melanoma tissue biopsies. High SERPINA3 expression was also associated with poor patient survival. In this study, we set out to test SERPINA3 proteins prognostic potential with a larger-sized and independent patient cohort, and to explore SERPINA3s function in melanoma cells. Tissue microarray-based immunohistochemistry analysis showed a significant increase in SERPINA3 expression in invasive and metastatic melanomas compared to normal nevi and melanoma-in-situ (P < 0.001, Chi-square test). In melanoma patients, high SERPINA3 expression was strongly associated with worse overall and disease specific survival at 5 years. Multivariate Cox regression analysis showed that SERPINA3 expression is an independent prognostic factor to predict melanoma patient clinical outcome. When SERPINA3 expression was selectively silenced using small interfering RNA molecules (siRNA) in cultured melanoma cell lines, cell migration and matrix invasion was significantly decreased, but no change in cell proliferation was observed. This study confirms the prognostic potential of SERPINA3 expression in human cutaneous melanoma and reveals the pro-migration and pro-invasion functions of this protein on melanoma cells.