Saturday July 2, 2016 (foodconsumer.org) -- A study published in 2015 in Science, a prestigious science journal, again indicates that high doses of vitamin C may be employed to cure cancers such as colorectal cancer with KRAS or BRAF mutations.  This research has not been widely publicized, but it is certainly good news for those who believe that vitamin C can cure or prevent cancer.

L. Yun at Weill Cornell Medical College in New York, New York and colleagues conducted the in vitro study to understand how high doses of vitamin C could have an anticancer activity if there is any against human colorectal cancers with either KRAS or BRAF mutations.   

The study showed high doses of vitamin C selectively killed cultured human colorectal cancer cells with KRAS or BRAF mutations.  The researchers found exposed to high doses of vitamin C, colorectal cancer cells increased uptake of the oxidized form of vitamin C called dehydroascorbic acid or dehydroascorbate through the GLU1 glucose transporter.

Increased uptake of this oxidized vitamin C caused oxidative stress and increased accumulation of reactive oxygen species, which eventually inactivated or inhibited glyceraldehyde 3-phosphate dehydrogenase (GAPDH), an enzyme that cancer cells need to generate energy.  As a result, the KRAS or BRAF mutant cancer cells died.

Also the study found high-dose vitamin C suppressed tumor growth in Apc/Kras(G12D) mutant mice.   This means that high doses of vitamin may also be effective at killing cancer cells in vivo.

The study suggests high doses of vitamin C may be used as a treatment for colorectal cancers carrying KRAS or BRAF mutations.

KRAS mutations are found at high rates in leukemia, colon cancer, pancreatic cancer, and lung cancer, according to wikipedia while more than 30 mutations in the KRAF gene have been identified and many of the mutations were seen commonly in papillary thyroid carcinoma, colorectal cancer, melanoma, and non-small-cell lung cancer.  (David Liu)

Yun J, Mullarky E, Lu C, Bosch KN, Kavalier A, Rivera K, Roper J, Chio II, Giannopoulou EG, Rago C, Muley A, Asara JM, Paik J, Elemento O, Chen Z, Pappin DJ, Dow LE, Papadopoulos N, Gross SS, Cantley LC., Vitamin C selectively kills KRAS and BRAF mutant colorectal cancer cells by targeting GAPDH.  Science. 2015 Dec 11;350(6266):1391-6.