Expression of C-KIT, CD24, CD44s, and COX2 in benign and non-invasive apocrine lesions of the breast

CD24 blockade as a novel strategy for cancer treatment

The CD24 protein is a heat-stable protein with a small core that undergoes extensive glycosylation. It is expressed on the surface of various normal cells, including lymphocytes, epithelial cells, and inflammatory cells. CD24 exerts its function by binding to different ligands. Numerous studies have demonstrated the close association of CD24 with tumor occurrence and progression. CD24 not only facilitates tumor cell proliferation, metastasis, and immune evasion but also plays a role in tumor initiation, thus, serving as a marker on the surface of cancer stem cells (CSCs). Additionally, CD24 induces drug resistance in various tumor cells following chemotherapy. To counteract the tumor-promoting effects of CD24, several treatment strategies targeting CD24 have been explored, such as the use of CD24 monoclonal antibodies (mAb) alone, the combination of CD24 and chemotoxic drugs, or the combination of these drugs with other targeted immunotherapeutic techniques. Regardless of the approach, targeting CD24 has demonstrated significant anti-tumor effects. Therefore, the present study focuses on anti-tumor therapy and provides a comprehensive review of the structure and fundamental physiological function of CD24 and its impact on tumor development, and suggests that targeting CD24 may represent an effective strategy for treating malignant tumors.

CD24, A Review of its Role in Tumor Diagnosis, Progression and Therapy

CD24, is a mucin-like GPI-anchored molecules. By immunohistochemistry, it is widely detected in many solid tumors, such as breast cancers, genital system cancers, digestive system cancers, neural system cancers and so on. The functional roles of CD24 are either fulfilled by combination with ligands or participate in signal transduction, which mediate the initiation and progression of neoplasms. However, the character of CD24 remains to be intriguing because there are still opposite voices about the impact of CD24 on tumors. In preclinical studies, CD24 target therapies, including monoclonal antibodies, target silencing by RNA interference and immunotherapy, have shown us brighten futures on the anti-tumor application. Nevertheless, evidences based on clinical studies are urgently needed. Here, with expectancy to spark new ideas, we summarize the relevant studies about CD24 from a tumor perspective.

Identification of the EMT-Related Genes Signature for Predicting Occurrence and Progression in Thyroid Cancer

BACKGROUND

The detection rate of thyroid cancer (TC) has been continuously improved due to the development of detection technology. Epithelial-mesenchymal transition (EMT) is thought to be closely related to the malignant progression of tumors. However, the relationship between EMT-related genes (ERGs) characteristics and the diagnosis and prognosis of TC patients has not been studied.

METHODS

Four datasets from Gene Expression Omnibus (GEO) were used to perform transcriptomic profile analysis. The overlapping differentially expressed ERGs (DEERGs) were analyzed using the R package "limma". Then, the hub genes, which had a higher degree, were identified by the protein-protein interaction (PPI) network. Gene expression analysis between the TC and normal data, the disease-free survival (DFS) analysis of TC patients from The Cancer Genome Atlas Thyroid Cancer (TCGA-THCA) cohort, function analysis, and immunohistochemistry (IHC) were performed to verify the importance of the hub genes. Finally, a prognostic risk scoring was constructed to predict DFS in patients with the selected genes.

RESULTS

A total of 43 DEERGs were identified and 10 DEERGs were considered hub ERGs, which had a high degree of connectivity in the PPI network. Then, the differential expressions of FN1, ITGA2, and KIT between TC and normal tissues were verified in the TCGA-THCA cohort and their protein expressions were also verified by IHC. DFS analysis indicated upregulations of FN1 expression (P<0.01) and ITGA2 expression (P<0.01) and downregulation of KIT expression (P=0.01) increased risks of decreased DFS for TCGA-THCA patients. Besides, by building a prognostic risk scoring model, we found that the DFS of TCGA-THCA patients was significantly worse in high-risk groups.

CONCLUSION

In summary, these hub ERGs were potential biomarkers for diagnosis and prognosis of TC, which can provide a basis for further exploring the efficacy of EMT in patients with TC.

Triple-negative apocrine carcinoma: A rare pathologic subtype with a better prognosis than other triple-negative breast cancers

BACKGROUND AND METHODS

Apocrine adenocarcinoma is a rare subtype of breast cancer. We sought to compare the characteristics and survival of patients diagnosed with triple-negative apocrine adenocarcinoma to those of patients diagnosed with triple-negative invasive ductal carcinoma. Utilizing data from the National Cancer Database between 2004 and 2013, 70 524 eligible female patients with triple-negative breast cancer were identified including 566 patients with apocrine adenocarcinomas and 69 958 patients with invasive ductal carcinoma. Descriptive statistics for each variable were reported. A comparison of each covariate between the study cohorts was assessed in univariate and multivariate analysis. Cox proportional models were used to calculate hazard ratios. Additionally, the propensity score matching method was implemented to reduce treatment selection bias.

RESULTS

Patients with triple-negative apocrine tumors were more likely to be older, Caucasian, and have smaller, moderately to well-differentiated tumors. Multivariable analysis noted a significantly improved survival for patients with triple-negative apocrine carcinoma (TNAC) vs triple-negative invasive ductal carcinoma (TNBC) (hazard ratio [HR] 0.65 [95% confidence interval [CI] [0.53-0.81], P = 0 < .001). Propensity score matching analysis confirmed a significant difference in overall survival for patients with TNAC in comparison to TNBC (HR 0.79 [95% CI [0.63-1.00], P = .05).

DISCUSSION

Triple-negative apocrine adenocarcinomas have a modestly improved long-term survival when compared with triple-negative invasive ductal cancers.

The diagnostic utility of EZH2 H-score and Ki-67 index in non-invasive breast apocrine lesions

In diagnostic breast pathology, there is no reliable applicable immunostain to help discern atypical and in situ apocrine lesions from benign apocrine tissue. At present, the diagnosis of non-invasive apocrine lesions remains challenging with current diagnoses rendered based on discrete morphologic characteristics on conventional hematoxylin and eosin staining. Interobserver variability is significant even among subspecialists partly due to lack of adjuvant diagnostic immunohistochemical stains. Herein, we set to elucidate the potential utility of EZH2 and Ki-67 immunostains as tangible tools in non-invasive apocrine proliferations. A cohort of apocrine breast lesions [Benign apocrine hyperplasia (BAH), n = 10; Atypical apocrine hyperplasia (AAH), n = 16; Apocrine ductal carcinoma in situ (ADCIS), n = 12] were subjected to EZH2 immunostaining and analyzed via H-scoring of nuclear expression. Mean H-scores for EZH2 progressively increased from BAH (23.5), to AAH (47.4) and ADCIS (196.4), and showed a significant difference utilizing the Kruskal-Wallis test (p < 0.0001). Further interrogation of Ki-67 demonstrated incremental expression from BAH to AAH and ADCIS at 1.6 %, 4.7 % and 24.7 %, respectively (p < 0.0001, Kruskal-Wallis test), suggesting an association with increased proliferation. Our results demonstrate that a combination of EZH2 and Ki-67 immunostaining may be employed in differentiating among challenging apocrine breast lesions and suggest a putative diagnostic utility for EZH2 and Ki-67 in non-invasive apocrine breast lesions.

Identification of kit-ligand a as the Gene Responsible for the Medaka Pigment Cell Mutant few melanophore

The body coloration of animals is due to pigment cells derived from neural crest cells, which are multipotent and differentiate into diverse cell types. Medaka (Oryzias latipes) possesses four distinct types of pigment cells known as melanophores, xanthophores, iridophores, and leucophores. The few melanophore (fm) mutant of medaka is characterized by reduced numbers of melanophores and leucophores. We here identify kit-ligand a (kitlga) as the gene whose mutation gives rise to the fm phenotype. This identification was confirmed by generation of kitlga knockout medaka and the findings that these fish also manifest reduced numbers of melanophores and leucophores and fail to rescue the fm mutant phenotype. We also found that expression of sox5, pax7a, pax3a, and mitfa genes is down-regulated in both fm and kitlga knockout medaka, implicating c-Kit signaling in regulation of the expression of these genes as well as the encoded transcription factors in pigment cell specification. Our results may provide insight into the pathogenesis of c-Kit-related pigmentation disorders such as piebaldism in humans, and our kitlga knockout medaka may prove useful as a tool for drug screening.

Loss of c-KIT expression in breast cancer correlates with malignant transformation of breast epithelium and is mediated by KIT gene promoter DNA hypermethylation

KIT Proto-Oncogene Receptor Tyrosine Kinase (KIT) is a transmembrane receptor tyrosine kinase which plays an important role in regulation of cell proliferation, survival and migration. Interestingly, the role of c-KIT in malignant transformation seems to be highly tissue-specific and it can act either as an oncogene or tumor suppressor gene. Here we analyzed the expression of c-KIT in normal breast tissues and tissues from different stages encompassing major steps of breast tumor development. Our study showed, that the c-KIT protein expression is gradually lost during the process of breast tissue transformation. The analysis of previously published datasets revealed that c-KIT expression in breast malignancies was downregulated at mRNA level. Because sequencing studies did not identify any recurrent mutations or copy number alterations, we proposed a potential epigenetic mechanism for the downregulation of c-KIT expression. In-silico analysis of the KIT promoter revealed the presence of CpG islands, therefore we performed bisulfite sequencing of normal breast epithelial tissues as well as breast tumor samples. We found, that KIT promoter is hypermethylated in breast tumors compared to normal breast tissues. Furthermore, treatment of breast cancer cell lines, that lack the expression of c-KIT, with methyltransferase inhibitor 5-Azacytidine (5Aza-2dC) resulted in increased expression of c-KIT mRNA. Collectively, our studies demonstrate that c-KIT expression is epigenetically downregulated during breast epithelium transformation and cancer development via KIT promoter hypermethylation.

Expression of CD24 and B7-H3 in breast cancer and the clinical significance

This study aimed to investigate the correlation between the expression of CD24 and B7-H3 in breast cancer tissues and the clinical significance. Expression of CD24 and B7-H3 in breast cancer and adjacent tissues were detected by immunohistochemistry. Quantitative PCR was used to detect the expression of CD24 and B7-H3 mRNA in breast cancer and adjacent tissues. The expression of CD24 and B7-H3 protein in breast cancer and adjacent tissues was detected by immunoblotting. The correlation between the expression levels of the two proteins was analyzed and the relationship between the expression of two proteins and the 5-year survival of breast cancer patients was investigated. CD24 and B7-H3 were positively expressed in breast cancer and adjacent tissues, the CD24-positive rate was 75.7 and 25.7%, respectively, and the B7-H3-positive rate was 56.8 and 43.2%, respectively, and the differences were statistically significant (P<0.05). The expression of CD24 was positively correlated with the expression of B7-H3 (Spearman's correlation coefficient r, 0.297; p=0.036). The positive and negative expression of CD24 and B7-H3 significantly affected the 5-year survival of breast cancer patients (P<0.05). Quantitative PCR results showed that the expression levels of CD24 and B7-H3 mRNA in breast cancer tissues were significantly higher than those in adjacent tissues (P<0.05). The expression levels of CD24 and B7-H3 protein in breast cancer tissues were also significantly higher than those in adjacent tissues (P<0.05). CD24 and B7-H3 were highly expressed in breast cancer, suggesting that both CD24 and B7-H3 were related to the development of breast cancer. Five-year survival analysis of breast cancer patients showed that the high expression of CD24 and B7-H3 were correlated with the poor prognosis of patients. Thus, CD24 and B7-H3 may become new targets for the treatment of breast cancer.

Loss of c-KIT expression in thyroid cancer cells

Papillary thyroid carcinoma is the most frequent histologic type of thyroid tumor. Few studies investigated the role of c-KIT expression in thyroid tumors, suggesting a role for this receptor and its ligand in differentiation and growth control of thyroid epithelium and a receptor loss following malignant transformation. We investigated and correlated c-KIT expression levels and two known markers of thyrocytes differentiation, PAX8 and TTF-1, in malignant and benign cytological thyroid samples. Moreover, we performed functional studies on human papillary thyroid carcinoma cell line to associated c-KIT expression to thyrocytes differentiation and tumor proliferation. c-KIT and PAX8 expression resulted higher in benign samples compared to the malignant ones, and the expression levels of these two genes were significantly correlated to each other. We also observed that c-KIT overexpression led to an increase of PAX8 expression level together with a decrease of proliferation. Furthermore, c-KIT overexpressing cells showed a regression of typical morphological features of malignancy. Taken together these results suggest that c-KIT could be involved in the differentiation of thyroid cells and in tumor progression.