Triple Negative Breast Cancer (TNBC) Cells Growth is Inhibited by High Dose Ascorbic Acid

• Published in: The FASEB journal Vol. 36; no. S1
• Main Author: Bennett, Lunawati L.
• Format: Journal Article
• Language: English
• Published: United States The Federation of American Societies for Experimental Biology 01-05-2022
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.2022.36.S1.0R245

Objective
According to the World Health Organization report, the incidence of breast cancer mortality is very high worldwide with 2.1 million women are being affected each year and death are estimated at 627,000 women. There are several subtypes of breast cancer. One of these subtypes is known as triple‐negative breast cancer (TNBC). TNBC doesn’t have the receptors for the hormone estrogen, nor progesterone, nor express HER2/neu; therefore, TNBC doesn’t respond to hormonal nor targeted therapies which makes TNBC difficult to treat.
The desired outcome of the cancer therapies is to decrease the proliferative activity of the cancer cells, to minimize drug resistance, and to decrease the toxicity of the anticancer drugs. Ascorbic acid has gained popularity as preventive agent for cancer due to its minimal cytotoxic to normal cellular tissue; however, the use of ascorbic acid for the treatment of cancer has controversial history. Taking oral ascorbic acid had no or little effect on cancer treatment, but recent discovery that intravenous ascorbic acid can provide 100‐fold higher plasma levels than oral intake has renewed interest on the role of ascorbic acid in the cancer treatment.
Hypothesis
At high dose (pharmacological concentrations), ascorbic acid may act as a prodrug to deliver extracellular H2O2 that is selectively toxic to cancer cells, but non‐toxic and well tolerated to normal cells. It is postulated that TNBC cells growth will be inhibited by high dose of ascorbic acid.
Methods
Ascorbic acid was buffered to pH 7 with sodium hydroxide and prepared immediately before use. MDA‐MB‐231 cells was used as TNBC model. MTT assay, Hoechst33342, H2DCFDA, and Rhodamine123 staining using fluorescent microscope were conducted to determine cell viability, chromatin inducing apoptosis, intracellular generation of ROS, and mitochondrial membrane potential, respectively. Western Blot to detect different signaling protein expressions such as Poly (ADP‐Ribose) polymerase (PARP), Casp‐3, Casp‐9, P‐53, Bax, Bcl2, Apaf‐1, MMP2, MMP 9, BRCA1, BRCA2, Bim, Map kinases were conducted to test the hypothesis that ascorbic acid was effective to kill TNBC cells.
Conclusion
This finding suggests that high dose ascorbic acid has a potential candidate as effective anti‐cancer for TNBC. At 1.6 mM, ascorbic acid killed MDA‐MB‐231, a TNBC cells by causing increased in caspase 3‐9 activities and by decreasing cell cycle regulatory proteins, Mitogen activated kinase 1‐4, and reactive oxygen species.