Previous studies detected no KRAS mutations in NPC specimens or cell lines [ 29, 40].
Breast tissue specimens or cell pellets were homogenised in 1 ml TRIzol® lysis reagent (Invitrogen) as previously described [ 27].
Total cellular RNA was isolated from tissue specimens or cell lines using the Trizol reagent (TaKaRa, Dalian, China), according to the manufacturer's instructions.
To investigate CSC properties such as tumor initiation and recurrence, many studies have examined methods for isolation of CSCs from cancer specimens or cell lines.
RNA was isolated from viably frozen specimens or cell lines growing in logarithmic phase using RNAqueous-4 PCR kits (Ambion corp, AM1914).
Genomic DNA was extracted from 30 pairs of gastric cancer tissues, 24 benign gastric mucosa with intestinal metaplasia, and 10 normal gastric specimens or cell lines by a DNA mini kit (Qiagen, Valencia, CA, USA).
For example, when studying cancer development, it is common to infer gene networks based on microarray data from different cancer specimens or cell lines separately and independently, despite that these biomaterials are usually collected over a contiguous disease progression course.
The spheroid culture system maintained in serum-free medium supplemented with growth factors established from colorectal cancer specimens or cell lines has been shown to be highly tumorigenic and to highly express LGR5.
All the steroidogenic enzymes necessary for the formation of androgens and estrogens from steroid precursors - steroid sulfatase, 17β-hydroxysteroid dehydrogenases (17β-HSDs), 3β-HSDs, 5α-reductases and aromatase - have been reported in normal mammary tissues, breast cancer specimens or cell lines [ 10].
Total RNA was extracted from breast tissue specimens or cells using the Trizol reagent (Invitrogen) following manufacturer's instructions.
