Neuronal differentiation in basal cell carcinoma: possible relationship to Hedgehog pathway activation?

Clinical and Molecular Features of Morpheaform Basal Cell Carcinoma: A Systematic Review

Basal cell carcinoma (BCC) is the most common skin cancer, with a lifetime risk currently approaching up to 40% in Caucasians. Among these, some clinical and pathological BCC variants pose a higher risk due to their more aggressive biological behavior. Morpheaform BCC (morBCC), also known as sclerosing, fibrosing, or morpheic BCC, represents up to 5-10% of all BCC. Overall, morBCC carries a poorer prognosis due to late presentation, local tissue destruction, tumor recurrence, and higher frequency of metastasis. In this systematic review, we review the epidemiological, clinical, morphological, dermatoscopical, and molecular features of morBCC. After the title and abstract screening of 222 studies and the full-text review of 84 studies, a total of 54 studies met the inclusion criteria and were thus included in this review.

CD56 and smooth muscle actin immunoreactivity in basal cell carcinomas: Are they indicators of differentiation or do they hold a diagnostic use?

BACKGROUND

Basal cell carcinoma (BCC) is the most common cutaneous malignancy and may show various differentiations. The possible pluripotent stem cell lineage of BCCs, whose origins are controversial today, is thought to be the main reason for the different morphologies. The aim of the study is to evaluate the expression of some neuroendocrine and smooth muscle markers of differentiation in BCCs and investigate the relationship between histopathologic subtypes and recurrence.

METHODS

A total of 128 cases diagnosed as BCC in our center were included. Immunohistochemical studies of CD56, synaptophysin, chromogranin-A, smooth muscle actin (SMA), desmin, caldesmon, and Ki67 were applied.

RESULTS

CD56, chromogranin-A, and synaptophysin immunoreactivity were detected in 77.3%, 13.3%, and 0.8% of the cases, respectively. 78.1% showed SMA positivity while no tumor expressed desmin or caldesmon. A correlation between histopathologic recurrence risk groups and CD56 expression was found (p < 0.05).

CONCLUSIONS

CD56 and SMA immunoreactivity is present in the majority of BCCs. However, the available findings do not support neuroendocrine or smooth muscle differentiation. CD56 antigen can be used for prognostic purposes in detecting high recurrence risk tumors. After the investigation of the expression rates of these two antigens in different cutaneous tumors, it may be appropriate to use them for diagnostic purposes in BCCs.

Sea turtle fibropapilloma tumors share genomic drivers and therapeutic vulnerabilities with human cancers

Wildlife populations are under intense anthropogenic pressures, with the geographic range of many species shrinking, dramatic reductions in population numbers and undisturbed habitats, and biodiversity loss. It is postulated that we are in the midst of a sixth (Anthropocene) mass extinction event, the first to be induced by human activity. Further, threatening vulnerable species is the increased rate of emerging diseases, another consequence of anthropogenic activities. Innovative approaches are required to help maintain healthy populations until the chronic underlying causes of these issues can be addressed. Fibropapillomatosis in sea turtles is one such wildlife disease. Here, we applied precision-medicine-based approaches to profile fibropapillomatosis tumors to better understand their biology, identify novel therapeutics, and gain insights into viral and environmental triggers for fibropapillomatosis. We show that fibropapillomatosis tumors share genetic vulnerabilities with human cancer types, revealing that they are amenable to treatment with human anti-cancer therapeutics.

David Duffy et al. use a precision-medicine-based approach to study fibropapillomatosis tumors in sea turtles to identify environmental triggers and potential therapeutics. They show that these tumors share genetic similarities with human cancer types, and may be treatable using human anti-cancer therapies.

Giant Basal Cell Carcinomas Express Neuroactive Mediators and Show a High Growth Rate: A Case-Control Study and Meta-Analysis of Etiopathogenic and Prognostic Factors

BACKGROUND

Giant basal cell carcinomas (GBCCs), (BCC ≥ 5 cm), are often painless, destructive tumors resulting from poorly understood patient neglect.

OBJECTIVES

To elucidate etiopathogenic factors distinguishing GBCC from basal cell carcinoma (BCC) and identify predictors for disease-specific death (DSD).

METHODS

Case-control study examining clinicopathologic and neuroactive factors (β-endorphin, met-enkephalin, serotonin, adrenocorticotropic hormone, and neurofilament expression) in GBCC and BCC. Systematic literature review to determine DSD predictors.

RESULTS

Thirteen GBCCs (11 patients) were compared with 26 BCCs (25 patients). GBCC significantly differed in size, disease duration, and outcomes; patients were significantly more likely to live alone, lack concern, and have alcoholism. GBCC significantly exhibited infiltrative/morpheic phenotypes, perineural invasion, ulceration, and faster growth. All neuromediators were similarly expressed. Adenoid phenotype was significantly more common in GBCC. Adenoid tumors expressed significantly more β-endorphin (60% vs. 18%, P = 0.01) and serotonin (30% vs. 4%, P = 0.02). In meta-analysis (n ≤ 311: median age 68 years, disease duration 90 months, tumor diameter 8 cm, 18.4% disease-specific mortality), independent DSD predictors included tumor diameter (cm) (hazard ratio (HR): 1.12, P = 0.003), bone invasion (HR: 4.19, P = 0.015), brain invasion (HR: 8.23, P = 0.001), and distant metastases (HR: 14.48, P = 0.000).

CONCLUSIONS

GBCC etiopathogenesis is multifactorial (ie, tumor biology, psychosocial factors). BCC production of paracrine neuromediators deserves further study.

GLI1 orchestrates CXCR4/CXCR7 signaling to enhance migration and metastasis of breast cancer cells

The up-regulation of chemokine receptors CXCR4 and CXCR7 impacts on the distant metastasis and prognosis of breast cancer, though knowledge about the regulatory mechanism of their expressions is limited. Meanwhile, the GLI transcription factors of Hedgehog signaling have been reported to play a pivotal role in the development and progression of many types of human cancer. In breast cancer, the increased expression of GLI1 correlated with metastasis and unfavorable overall prognosis, though its molecular mechanism is also not fully understood. Based on our findings that GLI1 enhanced the lung metastasis of breast cancer cells in a mouse model system, we comprehensively screened for genes up-regulated by GLI1 in breast cancer cells, and as such identified CXCR4, CXCR7/ACKR3, and actin-binding protein LCP1/L-PLASTIN, all of which have been reported to be involved in CXCL12-stimulating signaling. In breast cancer cells, we found that GLI1 and GLI2 up-regulated these expressions, while treatment with GLI-specific inhibitor GANT61 reduced the expressions. As for CXCR4, we confirmed it as a direct target of GLI1 through the reporter assay and the chromatin immunoprecipitation assay. We also found that GLI1 enhanced CXCL12-induced ERK phosphorylation and cell migration, both of which were blocked by either CXCR4-specific inhibitor or knockdown of CXCR7 or LCP1. These evidences suggest an indispensable role of GLI1 in the migration and metastasis of breast cancer cells through CXCL12/CXCR4 signaling enhancement.

UNC51-like kinase 1, autophagic regulator and cancer therapeutic target

Autophagy, the cell process of self-digestion, plays a pivotal role in maintaining energy homoeostasis and protein synthesis. When required, it causes degradation of long-lived proteins and damaged organelles, indicating that it may play a dual role in cancer, by both protecting against and promoting cell death. The autophagy-related gene (Atg) family, with more than 35 members, regulates multiple stages of the process. Serine/threonine protein kinase Atg1 in yeast, for example, can interact with other ATG gene products, functioning in autophagosome formation. One mammalian homologue of Atg1, UNC-51-like kinase 1 (ULK1) and its related complex ULK1-mAtg13-FIP200 can mediate autophagy under nutrient-deprived conditions, by protein-protein interactions and post-translational modifications. Although specific mechanisms of how ULK1 and its complex transduces upstream signals to the downstream central autophagy pathways is not fully understood, past studies have indicated that ULK1 can both suppress and promote tumour growth under different conditions. Here, we summarize some properties of ULK1 which can regulate autophagy in cancer, which may shed new light on future cancer therapy strategies, utilizing ULK1 as a potential new target.

GLI1 interferes with the DNA mismatch repair system in pancreatic cancer through BHLHE41-mediated suppression of MLH1

The mismatch repair (MMR) system is indispensable for the fidelity of DNA replication, the impairment of which predisposes to the development and progression of many types of cancers. To date, GLI1 transcription factor, a key molecule of the Hedgehog signaling pathway, has been shown to regulate the expression of several genes crucial for a variety of cancer cell properties in many types of cancers, including pancreatic ductal adenocarcinoma (PDAC), but whether GLI1 could control the MMR system was not known. Here, we showed that GLI1 and GLI2 indirectly suppressed the expression of MLH1 in PDAC cells. Through GLI1 target gene screening, we found that GLI1 and GLI2 activated the expression of a basic helix-loop-helix type suppressor BHLHE41/DEC2/SHARP1 through a GLI-binding site in the promoter. Consistent with a previous report that BHLHE41 suppresses the MLH1 promoter activity, we found that the activation of GLI1 led to the BHLHE41-dependent suppression of MLH1, and a double knockdown of GLI1 and GLI2 conversely increased the MLH1 protein in PDAC cells. Using TALEN-based modification of the MLH1 gene, we further showed that GLI1 expression was indeed associated with an increased tolerance to a methylating agent, methylnitrosourea cooperatively with a lower copy number status of MLH1. Finally, GLI1 expression was immunohistochemically related positively with BHLHE41 and inversely with MLH1 in PDAC cells and precancerous lesions of the pancreas. On the basis of these results, we propose that GLI1 depresses the MMR activity and might contribute to the development and progression of PDAC.

Immunohistochemistry: relevance in dermatology

Use of immunohistochemical technique is increasing in diagnosing various diseases. In many situations it may not be possible to differentiate entities with overlapping clinical and histopathological features. Immunostaining of cellular antigens is immensely helpful in such cases. Immunohistochemistry (IHC) has also been in use for targeted cancer therapy. In this article, the discussion will be restricted to use of IHC in dermatological disorders and use of classical antigens with brief updating of some important newly discovered antigens.

Expression and importance of zinc-finger transcription factor Slug in adenoid cystic carcinoma of salivary gland

BACKGROUND

It has been reported that zinc-finger transcription factor Slug plays a critical role in tumor proliferation and differentiation, relapse, invasion, metastasis, and decreased survival. However, there is little information on the expression and role of Slug in salivary adenoid cystic carcinoma (ACC).

METHOD

Demographic variables and primary tumor site, dates of diagnoses, perineural invasion, local regional recurrence, and distant metastasis of 121 cases of salivary ACC treated at the Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University between 1996 and 2005 were retrieved. The Slug expression of all these cases was examined by immunohistochemical methods. The association between Slug expression and clinicopathological variables was analyzed using Chi-squared test, and the prognostic factors were examined by univariate and multivariate analyses.

RESULTS

Our data demonstrated that the positive expression of Slug was observed in 71.90% (87/121) of cases. Slug expression was significantly associated with tumor site, TNM stage, histological pattern, perineural invasion, local regional recurrence and distant metastasis of patients with ACC (P<0.05). And Slug expression, local regional recurrence and distant metastasis were independent and significant prognostic factors in all patients.

CONCLUSIONS

It is proposed that Slug may play an important role in the invasion and metastasis of ACC, and that Slug had the potential for one of the strong invasion and metastasis indicators at presentation of ACC patients.