Cancer-associated fibroblasts (CAFs) play important roles in cancer progression through their complex interactions with cancer cells. The secreted bone morphogenetic protein antagonist, gremlin1 (GREM1) is expressed by the CAFs of basal cell carcinomas (BCCs), and promotes the growth of cancer cells. In this study, we investigated the expression of GREM1 mRNAs in various benign and malignant skin tumors, including various BCC subtypes. Analysis by RNA in situ hybridization (ISH) revealed that fibroblasts in the scar tissue expressed GREM1 and α-smooth muscle actin (α-SMA), whereas resident fibroblasts in the dermis of the normal skin did not express GREM1. Real-time polymerase chain reaction analysis showed significantly higher GREM1 expression in skin cancers and pilomatricomas (PMCs) than in other benign skin tumors. Tissue microarrays analyzed by RNA ISH for GREM1 expression also demonstrated that 23% of BCCs, 42% of squamous cell carcinomas, 20% of melanomas, and 90% of PMCs were positive for GREM1 expression, whereas trichoepitheliomas, eccrine poromas, hidradenomas, and spiradenomas were negative for GREM1 expression. Most BCCs that were GREM1 expression positive were of desmoplastic or mixed subtypes, and GREM1 expression was localized to activated myofibroblasts at the tumoral-stromal interface. Interestingly, most PMCs harbored GREM1-expressing fibroblasts, probably because of the inflammatory responses caused by foreign body reactions to keratin. Additionally, in BCCs, stromal GREM1 expression had a strong correlation with CD10 expression. In conclusion, GREM1 is frequently expressed by myofibroblasts in scars or in the stroma of basal cell carcinomas, suggesting that GREM1 expression can be a marker for activated myofibroblasts in the cancer stroma or in scar tissue.

A receptor tyrosine kinase for ephrin ligands, EPHB2, is expressed in normal colorectal tissues and colorectal cancers (CRCs). The aim of this study was to investigate EPHB2 expression over CRC progression and determine its prognostic significance in CRC. To measure EPHB2 mRNA and protein expression, real-time polymerase chain reaction and immunohistochemistry were performed in 32 fresh-frozen and 567 formalin-fixed paraffin-embedded CRC samples, respectively. We further investigated clinicopathological features and overall and recurrence-free survival according to EPHB2 protein expression. The EPHB2 level was upregulated in CRC samples compared to non-cancerous tissue in most samples and showed a strong positive correlation with AXIN2. Notably, CD44 had a positive association with both mRNA and protein levels of EPHB2. Immunohistochemical analysis revealed no difference in EPHB2 expression between adenoma and carcinoma areas. Although EPHB2 expression was slightly lower in invasive fronts compared to surface area (p < .05), there was no difference between superficial and metastatic areas. EPHB2 positivity was associated with lymphatic (p < .001) and venous (p = .001) invasion, TNM stage (p < .001), and microsatellite instability (p = .036). Kaplan-Meier analysis demonstrated that CRC patients with EPHB2 positivity showed better clinical outcomes in both overall (p = .049) and recurrence-free survival (p = .015). However, multivariate analysis failed to show that EPHB2 is an independent prognostic marker in CRCs (hazard ratio, 0.692; p = .692). Our results suggest that EPHB2 is overexpressed in a subset of CRCs and is a significant prognostic marker.

Lee JY, et al. J Korean Med Sci. 2012 Jun;27(6):661-667. https://doi.org/10.3346/jkms.2012.27.6.661

Basal cell carcinoma (BCC) is the most common human cancer, characterized by aberrant activation of the hedgehog (HH) signaling pathway resulting from mutations in the patched 1 (PTCH1) or smoothened (SMO) genes. In the present study, to uncover the expression profile of HH signaling-related molecules, we thoroughly examined the mRNA and protein expression levels of six molecules including GLI1, GLI2, PTCH1, PTCH2, SHH, and SMO in BCC and various other cutaneous tumors. Real-time PCR analysis demonstrated that BCC showed remarkably enhanced mRNA expression of all HH molecules, except SMO compared to other skin tumors. However, immunohistochemical analysis revealed that only GLI1 protein was specifically upregulated in BCC, while the other HH-related proteins did not show any significant differences between the tumors. Notably, other skin malignancies such as squamous cell carcinoma, sebaceous carcinoma, and malignant melanoma showed no GLI1 expression and there was no difference in GLI1 expression between the BCC subtypes. In addition, GLI1 and GLI2 expression were strongly associated with the hair follicle stem cell markers, LGR4 and LGR5, which are known target genes of the Wnt pathway. Our results suggest that GLI1 has the potential to be a diagnostically useful marker for differentiating BCC from other skin malignancies and an interaction between the HH and Wnt signaling pathways may be involved in the development of BCCs.

Secreted Protein Acidic and Rich in Cysteine (SPARC)-related modular calcium-binding protein-2 (SMOC2), a secreted matricellular protein, is reported to be involved in various processes related to cancer progression such as regulating the cell cycle, angiogenesis, and invasion. However, its expression and prognostic significance in papillary thyroid carcinomas (PTCs) remains unknown. Using immunohistochemistry, we evaluated the expression profile of SMOC2 and its prognostic value in a large cohort of PTCs. Real time-PCR analysis with fresh-frozen tissues showed that SMOC2 mRNA expression in PTCs was substantially lower than the expression in matched non-cancerous thyroid tissues, consistent with the results from thyroid cancer cell lines. Immunohistochemical analysis demonstrated that SMOC2 was normally present in thyroid follicular epithelial cells and the expression level was maintained in nodular hyperplasia. However, SMOC2 expression was significantly lower in lymphocytic thyroiditis and follicular tumors including follicular adenomas and carcinomas. In particular, 38% of PTCs exhibited a complete loss of SMOC2 expression, which was associated with the presence of BRAF (V600E) mutation. Moreover, SMOC2 further declined during lymph node metastasis in PTCs. DNA methylation chip analysis revealed one hypermethylated CpG site in the promoter region of SMOC2 gene, suggesting an epigenetic regulation of SMOC2 in PTCs. Remarkably SMOC2 positivity was associated with improved recurrence-free survival along with female sex, tumor size, and the N stage. However, SMOC2 was not identified as an independent prognostic marker in multivariate analyses. Taken together, SMOC2 expression is significantly down-regulated in PTCs and SMOC2 positivity is closely associated with better clinical outcomes, suggesting that SMOC2 can be a prognostic marker in PTC patients.

Background Gastric intestinal metaplasia (GIM), particularly the incomplete subtype (Inc IM), is strongly associated with increased gastric cancer (GC) risk. However, its role as a true precursor lesion remains uncertain. Objective We aimed to delineate the molecular identity, differentiation potential and oncogenic relevance of Inc IM. Methods Spatial transcriptomics using a custom lineage-enriched panel was applied to profile GIM and GC tissues. Subtype-specific GIM organoid models were developed for DNA methylation and chromatin accessibility profiling. Single-cell RNA sequencing was performed to evaluate differentiation capacity. Results Spatial transcriptomics revealed that Inc IM potentially originates from the deep antral gland cells and harbours a hybrid transcriptomic signature incorporating gastric, small intestinal and large intestinal lineages across both differentiated and stem/progenitor compartments. DNA methylation profiling of subtype-specific organoids showed that Inc IM exhibits extensive intergenic hypermethylation, resembling native antral mucosa. In contrast, complete subtype was marked by promoter hypermethylation of tumour suppressor genes and displayed a more fully intestinalised epigenetic profile. Organoid models recapitulated subtype-specific traits and demonstrated lineage plasticity. Spatial mapping of GC samples revealed an enrichment of Inc IM-like cells, particularly within microsatellite stable tumours. Approximately 76% of the GCs analysed were linked to GIM, while the remaining (24%) appeared to be associated with deep antral differentiation. Conclusions Inc IM represents a phenotypically unstable and epigenetically deregulated metaplastic state with dual-lineage potential and molecular resemblance to GC. These findings establish Inc IM as a true precursor to GC and underscore the importance of active surveillance and early intervention strategies.