Spheroid-Derived Cells From Renal Adenocarcinoma Have Low Telomerase Activity and High Stem-Like and Invasive Characteristics

Abstract

Cancer stem cells (CSCs) are a theorized small subpopulation of cells within tumors thought to be responsible for metastasis, tumor development, disease progression, treatment-resistance, and recurrence. The identification, isolation, and biological characterization of CSCs may therefore facilitate the development of efficient therapeutic strategies targeting CSCs. This study aims to compare the biology and telomerase activity of CSCs to parental cells (PCs) in renal cancer. Renal CSCs were enriched from the ACHN cell line using a sphere culture system. Spheroid-derived cells (SDCs) and their adherent counterparts were compared with respect to their colony and sphere formation, expression of putative CSC markers, tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, and invasiveness. The expression of genes associated with CSCs, stemness, EMT, apoptosis, and ABC transporters was also compared between the two populations using quantitative real-time PCR (qRT-PCR). Finally, telomerase activity, hTERT expression, and sensitivity to MST-312, a telomerase inhibitor, was investigated between the two populations. We demonstrated that a subpopulation of ACHN cells was capable of growing as spheroids with many properties similar to CSCs, including higher clonogenicity, superior colony-and sphere-forming ability, and stronger tumorigenicity and invasiveness. In addition, SDCs demonstrated a higher expression of markers for CSCs, stemness, EMT, apoptosis, and ABC transporter genes compared to PCs. The expression of hTERT and telomerase activity in SDCs was significantly lower than PCs; however, the SDC population was more sensitive to MST-312 compared to PCs. These findings indicate that the SDC population exhibits stem-like potential and invasive characteristics. Moreover, the reduced expression of hTERT and telomerase activity in SDCs demonstrated that Saeednejad Zanjani et al. Telomerase Reduces in Renal CSCs the expressions of hTERT and telomerase activity are not always higher in CSCs. Our results also showed that MST-312 treatment inhibited SDCs more strongly than PCs and may therefore be useful as a complementary targeted therapy against renal CSCs in the future.

The Mangrove-Derived Diterpenoid Diaporthe B Inhibits the Stemness and Increases the Efficacy of Docetaxel in Prostate Cancer PC-3 Cells

“…The size of spheres after 12-day cultures was around 50-200 μm. The morphology of the spheres was similar to those derived from other tumors such as lung and renal cancers 28,29 . As shown in Figure 2F, the resistant cells had much higher sphere-forming efficiency than the parental PC-3 cells.…”

Exploration of the cancer genome atlas database reveals genes of interest related with cancer cell stemness indices in clear cell renal cell carcinoma

“…Cancer cell stemness is implicated in vital cancerous activities such as proliferation and metastasis [ 14 , 15 ]. Integrated analysis of cancer cell stemness and tumor tissue expression profiles offered a better understanding in avant-garde fields like immune microenvironment and prognostic model [ 6 , 7 , 8 ], which is essential in today’s world where accumulating emphasis has been put on individualized medicine.…”

Nanog is a promising chemoresistant stemness marker and therapeutic target by iron chelators for esophageal cancer

“…5,26 These show partial overlap with other cancers. [27][28][29] Nanog is reportedly expressed in other gastrointestinal cancers and is known as an important stemness marker to acquire stemness potential. [29][30][31] No CSC-targeting drugs have been established, although many candidate drugs have been developed.…”

“…Some stemness markers, including Nanog, and key signal pathways such as Wnt/β‐catenin, Notch and JAK/STAT3 are known as characteristics of CSCs in esophageal cancer 5,26 . These show partial overlap with other cancers 27‐29 . Nanog is reportedly expressed in other gastrointestinal cancers and is known as an important stemness marker to acquire stemness potential 29‐31 .…”