#Question id: 1537
#Unit 4. Cell Communication and Cell Signaling
Transformation of mature cells may also occur due to aberrant expression of stemness genes, resulting in cell clones with a dedifferentiated phenotype and self-renewing capacity resembling stem cells. Recent experimental evidence supporting this proposal has been provided with the induction of adult somatic cells into pluripotent stem (iPS) cells through ectopic expression of four genes encoding the pluripotency factors Oct4 and Sox2, the transcription factor Klf4, and the oncoprotein c-Myc in mouse or human fibroblasts. However, along with pluripotency comes the capability of generating teratomas. On the basis of the above information which of the following outcome is most appropriate?
#Question id: 1538
#Unit 4. Cell Communication and Cell Signaling
Many aspects of the biology of stem cells, including maintenance of pluripotency, self-renewal, and differentiation, are controlled by the phenomenon of RNA interference involving a variety of small molecules of RNA.
Match the following miRNA (Column I) with their target gene (Column II).
Column I |
Column II |
a. Let-7 miRNA |
i. Bcl-2 |
b. miR-16 |
ii. PTEN phosphatase |
c. miR-125a and miR-125b |
iii. Myc |
d. miR-21 |
iv. LIN28 |
#Question id: 15303
#Unit 4. Cell Communication and Cell Signaling
#Question id: 15304
#Unit 4. Cell Communication and Cell Signaling
#Question id: 15305
#Unit 4. Cell Communication and Cell Signaling
#Question id: 15306
#Unit 4. Cell Communication and Cell Signaling
The transformation of a normal cell to a cancer cell is accompanied by the loss of function of one or more tumor‐suppressor genes. High‐throughput sequencing studies have identified hundreds of genes that are implicated as tumor suppressors in humans. Some of the better characterized genes;
Gene |
Primary tumor |
Proposed function |
i) APC |
Colorectal |
Binds β
‐catenin acting as transcription factor |
ii) BRCA1 |
Breast |
DNA repair |
iii) MSH2, MLH1 |
Melanoma, pancreatic |
p16: Cdk inhibitor ARF: stabilizes p53 |
iv) E‐Cadherin |
Breast, colon |
Cell adhesion molecule |
v) INK4a |
Colorectal |
Mismatch repair |
vi) NF1 |
Neurofibromas |
Activates GTPase of Ras |
Choose incorrect matching regarding tumor‐suppressor genes/primary tumor/proposed functions; |