Investigation of biomarker in laryngeal carcinomas

OTX1 exerts an oncogenic role and is negatively regulated by miR129-5p in laryngeal squamous cell carcinoma

Background

Orthodenticle homeobox 1 (OTX1) is a transcription factor that plays an important role in various human cancers. However, the function of OTX1 in laryngeal squamous cell carcinoma (LSCC) is largely unknown. We aimed to explore the roles of OTX1 in LSCC and its possible molecular mechanism.

Methods

The expression levels of OTX1 were assessed in LSCC cell lines and tissue samples. We further examined the effect of OTX1 on LSCC progression. The upstream regulator of OTX1 was identified using a computer algorithm and confirmed experimentally.

Results

OTX1 was highly expressed in 70.7% (70/99) of LSCC tissue samples. The OTX1 expression in LSCC was significantly correlated with lymph node metastasis. High OTX1 expression in patients with LSCC was correlated with poor prognosis. Knockdown of OTX1 inhibited proliferation, colony formation, migration and invasion in LSCC cells. Knockdown of OTX1 inhibited tumor growth in a xenograft mouse model. Mechanistically, OTX1 might act as a direct target of miR-129-5p. OTX1 enhanced tumorigenicity and tumor growth both in vitro and in vivo.

Conclusions

Our findings support that OTX1 is an oncogene in LSCC tumorigenesis and progression. Furthermore, OTX1 is a direct target of miR-129-5p in LSCC cells. Taken together, OTX1 is a promising diagnostic and therapeutic marker for LSCC.

The long noncoding RNA ST7-AS1 promotes laryngeal squamous cell carcinoma by stabilizing CARM1

The laryngeal squamous cell carcinoma (LSCC) represents a malignant cancer and contributes largely to head and neck tumorigenesis. The molecular mechanisms for LSCC progression are poorly understood. In current work, we identified long non-coding RNA (lncRNA) termed suppressor of tumorigenicity 7 antisense RNA 1 (ST7-AS1) as an oncogenic factor in LSCC. ST7-AS1 is frequently overexpressed in LSCC tissues and cell lines. ST7-AS1 is required for the malignancy of LSCC cells through migration, tumor sphere formation assay and in vivo implantation. Mechanistically, ST7-AS1 could interact with CARM1, a well characterized protein arginine methyltransferase and protect CARM1 from ubiquitin-dependent degradation. CARM1 can methylate Sox-2, a pluripotent transcription factor. Thus, ST7-AS1 might mediate its oncogenic effect by signaling through CARM1-Sox-2 axis to enhance Sox-2 self-association and transactivation activity. Collectively, we have unraveled a ST7-AS1/CARM1/Sox-2 signaling axis in LSCC and may have created novel interconnections between noncoding RNAs and cancer development.

Long non-coding RNA AC026166.2-001 inhibits cell proliferation and migration in laryngeal squamous cell carcinoma by regulating the miR-24-3p/p27 axis

Long non-coding RNA (lncRNA) AC026166.2-001 was found to be down-regulated in laryngeal squamous cell carcinoma (LSCC) tissues and metastatic neck lymph nodes. Decreased AC026166.2-001 was associated with poorer prognosis and may act as a novel biomarker for LSCC patients. In this study, AC026166.2–001 was overexpressed by a lentivirus vector and down-regulated by a small interfering RNA (siRNA). The results of real-time cell analysis (RTCA) and a plate colony formation assay showed that AC026166.2–001 inhibited LSCC cell proliferation and the clone-forming capacity. Cell cycle distribution and related protein changes were measured by flow cytometry. AC026166.2–001 arrested the cell cycle at the G1 phase and induced apoptosis. In addition, AC026166.2–001 decreased cell migration as measured by wound healing assays and transwell migration assays. Moreover, luciferase reporter assay and Western blotting results suggested that AC026166.2–001 acts as a sponge of miR-24-3p and regulates the expression of p27 and cyclin D1. The in vivo results showed that AC026166.2–001 significantly suppressed the growth of LSCC xenografts and promoted apoptosis. We validated the molecular mechanisms underlying AC026166.2–001 in LSCC. This is the first report of AC026166.2–001 acting as a tumor suppressor in LSCC by regulating the miR-24-3p/p27 axis.

Expression of Podoplanin in Laryngeal Squamous Cell Carcinoma and Dysplasia

INTRODUCTION

In human cancers, podoplanin expression and its correlation with tumour invasive potential raise its possible role as a diagnostic and prognostic marker for cancer.

AIM

To investigate the immunohistochemical expression of podoplanin in laryngeal Squamous Cell Carcinoma (SCC) and dysplasia.

MATERIALS AND METHODS

This study included a total of 60 archived, formalin fixed, paraffin embedded tissue blocks of 40 cases of laryngeal SCC and 20 cases of dysplastic lesions. The samples were immunohistochemically analysed for podoplanin expression.

RESULTS

Podoplanin expression was significantly higher in laryngeal SCC (90%) than laryngeal dysplastic lesions (55%) (p-value=0.002). The expression of podoplanin was significantly increased with the higher grades of dysplasia (p-value=0.016). A significant positive correlation was detected between podoplanin expression in laryngeal SCC and depth of tumour invasion (p-value=0.035), and stage (p-value=0.026).

CONCLUSION

The high expression of podoplanin in laryngeal SCC and its significant correlation with poor prognostic parameters recommends podoplanin as a prognostic marker in laryngeal SCC. In addition, increased podoplanin expression with higher grades of dysplasia, supports its role in malignant transformation and allows us to recommend its evaluation in premalignant lesions.