Hyaluronan (HA), one of the major ECM (extracellular matrix) components have been identified as a physiological ligand for surface CD44 isoforms which are frequently overexpressed in malignant tumor cells during cancer progression.
CD44/MyD88 co-expression was associated with tumor progression, metastasis, and recurrence in advanced EOC, and an independent prognostic factor for disease-free survival and overall survival.
CD44 is an adhesion protein involved in tumour progression, metastasis and stemness in different cancers; however, there has been controversies about the significance of CD44 expression in neuroblastoma and its relationship with tumour progression.
The cell membrane receptor CD44 is associated with cancer progression and has been recognized as a cancer stem cell marker including ovarian cancer, becoming a suitable candidate to be targeted by gPTX-L therapy.
Cluster of differentiation 44 (CD44) is a receptor for hyaluronic acid (HA) and HA-binding has been proven to participate in various biological tumor activities, including tumor progression, metastasis and drug resistance.
Higher CD44 expression was associated with more aggressive behavior, tumor progression and worse prognosis in clear cell RCC (ccRCC) but not in papillary and chromophobe RCC subtypes.
Higher expression of CD44 in the tumor periphery than in the core was correlated with a highly invasive feature on MRI and was associated with early tumor progression and worse survival, whereas lower expression of CD44 in the tumor periphery corresponded to low invasion and was associated with longer survival.
Ectopic expression of KLF4 increased the sphere formation ability and CD44/133-positive cell numbers, which can be reversed by abundant expression of miR-124, suggesting that KLF4 is a functional target of miR-124 in tumourigenesis and cancer progression of HCC.
Overexpression of variant isoforms of CD44 (CD44v) is most commonly linked to cancer progression, whereas their loss is associated with inhibition of tumor growth.
Downregulation of AZGP1 by Ikaros and histone deacetylase promotes tumor progression through the PTEN/Akt and CD44s pathways in hepatocellular carcinoma.
In conclusion, our findings revealed that EMP3 might be a potential target for CD44-high GBMs and highlight the essential functions of EMP3 in TGF-β/Smad2/3 signaling activation and tumor progression.
The overexpression of CD44 in cancer cells reroutes number of oncogenic pathways including the central Pi3K/Akt/NF-kB pathway leading to cancer progression and malignancy.
We defined a parameter CD44/CD24 ratio to present the expression level of CD44 and CD24 and found that high CD44/CD24 ratio and ALDH1<sup>+</sup> are both indicators for cancer malignancy, but play different functions during tumor progression.
Hyaluronan (HA), an important glycosaminoglycan component of the extracellular matrix (ECM), and its major cell surface receptor, CD44, have been suggested to be important cellular mediators influencing tumor progression and treatment resistance in head and neck cancer.
While several studies link the cell-surface marker CD44 to cancer progression, conflicting results show both positive and negative correlations with increased CD44 levels.
This new knowledge could provide the groundwork necessary for establishing new tumor markers and developing important, novel drugs targeted against HA/CD44-associated tumor progression, which can be utilized in the therapeutic treatment of metastatic cancer patients.
Additional subsets of CTCs within individual patients were characterized by divergent expression of genes involved in epithelial-mesenchymal transition (e.g., CDH2, MMPs, VIM, or ZEB1 and 2), DNA repair (RAD51), resistance to cancer therapy (e.g., AR, AR-V7, ERBB2, EGFR), cancer stemness (e.g., CD24 and CD44), activated signaling pathways involved in tumor progression (e.g., PIK3CA and MTOR) or cross talks between tumors and immune cells (e.g., CCL4, CXCL2, CXCL9, IL15, IL1B, or IL8).