CD24+CD44+CD54+EpCAM+ gastric cancer stem cells predict tumor progression and metastasis: clinical and experimental evidence

BACKGROUND

Gastric cancer (GC) is a leading cause of cancer-related deaths worldwide. Specific and thorough identification of cancer cell subsets with higher tumorigenicity and chemoresistance, such as cancer stem cells (CSCs), could lead to the development of new and promising therapeutic targets. For better CSC identification, a complete or extended surface marker phenotype is needed to provide increased specificity for new cell targeting approaches. Our goal is to identify and characterize a putative extended phenotype for CSCs derived from patients with GC before treatment, as well as to evaluate its clinical value. In addition, we aim to ensure that cells with this phenotype have stemness and self-renewal capabilities.

METHODS

This is a cohort study including 127 treatment-naïve patients with GC who attended the Instituto Nacional de Cancerología. Multiparametric flow cytometry analysis was performed to determine the extended phenotype of cells derived from gastric biopsies. The tumorigenic capability of cells identified in patients was assessed in a zebrafish model.

RESULTS

CD24+CD44+CD54+EpCAM+ cells were present in all treatment-naïve patients included, with a median abundance of 1.16% (0.57-1.89%). The percentage of CD24+CD44+CD54+EpCAM+ cells was categorized as high or low using 1.19% as the cutoff for the CD24+CD44+CD54+EpCAM+ cell subset. Additionally, a higher TNM stage correlated with a higher percentage of CD24+CD44+CD54+EpCAM+ cells (Rho coefficient 0.369; p < 0.0001). We also demonstrated that a higher percentage of CD24+CD44+CD54+EpCAM+ cells was positively associated with metastasis. The metastatic potential of these cells was confirmed in a zebrafish model. Ultimately, under our conditions, we conclude that CD24+CD44+CD54+EpCAM+ cells are true gastric cancer stem cells (GCSCs).

CONCLUSION

The CD24+CD44+CD54+EpCAM+ cells present in tissue samples from patients are true GCSCs. This extended phenotype results in better and more specific characterization of these highly tumorigenic cells. The relative quantification of CD24+CD44+CD54+EpCAM+ cells has potential clinical value, as these cells are associated with metastatic disease, making their presence an additional prognostic marker and possibly a target for the design of new antineoplastic treatments in the era of precision oncology. Overall, the extended CD24+CD44+CD54+EpCAM+ phenotype of GCSCs could support their isolation for the study of their stemness mechanisms, leading to the identification of better molecular targets for the development of both new therapeutic approaches such as oncoimmunotherapy and new diagnostic and clinical prognostic strategies for GC.

Prognostic importance of DNA from human papillomavirus in patients with oral squamous cell carcinoma

Background

Survival of patients with oral squamous cell carcinoma (OSCC) is generally low, with the likelihood of locoregional recurrence or disease progression (LR/DP). Knowledge of prognostic factors for survival is key to achieving an understanding and increased survival. The present study aimed to identify prognostic factors for patients with OSCC, especially the presence of DNA from human papillomavirus (HPV).

Material and Methods

Retrospective cohort study including 119 patients with OSCC treated at the National Cancer Institute in Mexico City (2009-2013). Clinical information was obtained from patient records including LR/DP. Formalin-fixed, paraffin-embedded tissues were obtained and used for detecting DNA from different types of HPV. Potential prognostic factors for Overall Survival (OS) were analyzed using the Cox proportional hazards model.

Results

After model adjustment, factors associated with longer OS were a pre-treatment platelet count above 400,000/mm3 (HR=0.09, p=0.026) and response to primary treatment (HR=0.26, p=0.001). HPV DNA was present in 23 (19.3%) of the patients and importantly, type 16 found in 19 of them. Although survival of HPV-positive patients was longer, difference was not significant. However, among patients with LR/DP, HPV positivity was significantly associated with increased survival (HR=0.23, p=0.034). Importantly, survival was significantly different for HPV-positive patients with LR/DP > 6 months (HR=0.20, p=0.002), had higher absolute lymphocyte count at start of treatment (HR=0.50, p=0.028) or had local rescue treatment (HR=0.24, p=0.019).

Conclusions

Although HPV positivity was not associated with a longer OS of OSCC patients, a better prognosis was significantly associated with HPV positivity and recurring or progressing disease, particularly with HPV type 16.

Key words:HPV, human papillomavirus, HPV-16, oral squamous cell carcinoma, oral cancer, survival, locoregional recurrence, disease progression.