Table 1.

Major factors promoting metastasis and stemness in tumors.

Tumor type	Stemness & Metastatic determinants	Cell-of-origin	Ref.
Renal cell carcinoma	Ongoing clonal evolution; de-differentiation and ploidy status	Progenitor cells of metastasis and primary tumor cells	5, 15
Oral squamous cell carcinoma	Drug transporter proteins and ploidy status	Transient shift between multiple tumorigenic fractions	16
Breast cancer	Evolution of six distinct PTEN mutations	Selective enrichment of metastatic, therapy resistant clones	19
Ovarian serous adenocarcinoma	Mutant mitochondrial DNA profile in tumorigenic CSC clones	19 immortalized stem and progenitor clones from single tumor sample	21
Colon cancer	Deletion of APC gene	Intestinal stem cells form adenomas; transient amplifying cells result in microadenomas	24
Prostate cancer	MYC amplification and PTEN loss	Well-differentiated acinar adenocarcinoma, androgen receptor (AR) and prostate-specific antigen (PSA) positive originated from Luminal epithelial cells; Basal epithelial cells generated more aggressive tumors and low/absent AR and PSA expression	25
Papillary thyroid carcinoma	Senescent-associated secretory phenotype (SASP).	Promote collective invasion of non-senescent tumor cells	41
Leukemia	BCR-ABL-independent mechanisms	Survival of leukemic stem cells (LSCs) Minimal residual disease or Persister cells with increased stem cell characteristics and quiescence	60
Pancreatic ductal adenocarcinoma (PDAC)	High CD9 expression; high glutamine uptake and cell surface expression of the glutamine transporter ASCT2	Tumor-initiating cells (TICs) enhanced tumorigenicity.	62
Ovarian cancer	Transdifferentiation to tumor-derived endothelial cells, pericytes and lymphatic endothelial cells	Ovarian CSCs	63
Glioblastoma (GBM)	Transdifferentiation into Tumor Derived Endothelial Cells (TDEC)	GBM stem-like cells (GSC)	64