22. Following statements have been proposed for cancer cells and cancer stem cells:
    A. Cancer cells mostly have mutations whereas cancer stem cells do not.
    B. Cancer cells divide to form two different populations of cells whereas cancer stem cells do not divide.
    C. Cancer stem cells can undergo self-renewal whereas cancer cells cannot.
    D. Cancer cells are predominantly resistant to chemotherapy and radiation.
    E. Cancer stem cells are found only in the bone marrow and placenta.
    Which one of the following combination of statements is correct?
    (1) A and C (2) A and B
    (3) C and E (4) C and D

The correct combination of statements about cancer cells and cancer stem cells is:

(4) C and D

Explanation:

• Statement C: Cancer stem cells can undergo self-renewal, whereas regular cancer cells generally cannot. This is a fundamental property of cancer stem cells (CSCs), enabling them to maintain tumor growth and generate heterogeneity within tumors.​

• Statement D: Cancer cells are predominantly resistant to chemotherapy and radiation. This often relates to cancer stem cells within tumors, which tend to be more resistant to conventional treatments, leading to relapse and metastasis.​

• Incorrect statements include:

  • A: Cancer stem cells do have mutations; they are not mutation-free compared to other cancer cells.

  • B: Both cancer cells and cancer stem cells divide, but cancer stem cells have the ability for asymmetric division leading to different cell populations.

  • E: Cancer stem cells are found in many tumor types and tissues, not exclusively in bone marrow and placenta.