Cervical Health Awareness Month: Testing C-Phycocyanin on Cervical Cancer Cells
January is Cervical Health Awareness Month and highlights issues related to cervical cancer, HPV disease, the importance of early detection, and organizations that provide resources to educate the public and healthcare providers about cervical health (1). According to the American Cancer Society, about 14,480 new cases of invasive cervical cancer will be diagnosed in 2021 (2).
Cervical cancer is a type of cancer that starts in the cells lining the cervix. Various strains of the human papillomavirus (HPV), a sexually transmitted infection, play a role in causing most cervical cancer (3). When the body is exposed to HPV, the immune system will usually prevent the virus from causing harm. However, for some women, HPV survives for years and contributes to the process that causes some cervical cells to become cancerous (3).
Cervical cancer used to be one of the most common causes of cancer death for American women (2). Over the years, there have been great strides in the development of cervical cancer screening programs, early diagnosis and treatment of cervical cancer and precancerous lesions (4). However, for women with advanced or metastatic cervical cancer the therapeutic effects are not as adequate (4). According to Ji et al. (2020), most patients with cervical cancer die of metastasis (4), which is when cancer cells spread from the place where they originally formed to another part of the body (5).
In metastasis, cancer cells break away from where they were originally formed, travel through the blood or lymph system, and invade other organs or tissues of the body. The new, metastatic tumor is the same type of cancer as the primary tumor. The National Cancer Institute gives this example: If breast cancer spreads to the lung, the cancer cells in the lung are breast cancer cells, not lung cancer cells (5).
Ji et al. (2020), believes that epithelial-to-mesenchymal transition, aka EMT (a biological process where epithelial cells are transformed into mesenchymal phenotype cells), is a “pivotal and intricate process that increases the metastatic potential of cervical cancer.” The aim of their study was to explore how C-phycocyanin (C-PC) inhibits the migration and invasion of cervical cancer cells, thus providing a new concept for the treatment and prognosis of cervical cancer (4).
C-phycocyanin (C-PC) is a natural marine product found in some blue-green microalgae such as Spirulina platensis (4). It is a protein-bound pigment soluble in water and used in many countries as a dietary supplement (6). C-PC has previously been investigated for its health benefits including studies on improving human immunity, anti-oxidation, anti-inflammatory, and anti-tumor. Its anti-cancer effects have also been studied on various types of cancer including cervical, pancreatic, non-small cell lung, and breast cancers. However, the effect of C-PC on EMT needed more thorough research (4).
Specifically, Ji et al. (2020) performed a wound-healing assay, an invasion assay, an immunofluorescence assay, a western blot, a flow cytometry, and a real-time reverse transcription polymerase chain reaction in cervical cancer Caski cell lines. Additionally, they evaluated the TGF-β/smad signaling pathway in the Caski cell lines (4).
The study yielded several results that showed the benefits of treating cervical cancer Caski cells with C-PC (4):
1. C-PC can inhibit the TGF-β1 induced migration and invasion of Caski cells
2. C-PC can reduce the expression levels of transcription factors Twist, Snail, Zeb1
In this study, the mRNA expression level of Twist (can promote tumor invasion and metastasis), Snail (promotes the transformation of epithelial cells to mesenchymal cells), and Zeb1 (suppresses the transcription of E-cadherin) was significantly up-regulated in the cells treated with TGF-β1, but down-regulated by C-phycocyanin. The results suggest that C-PC may inhibit the EMT of Caski cells by down-regulating the expression of the three transcription factors listed above and prevent the TGF-β1-induced migration and invasion of Caski cells.
Further results indicated that (4):
3. C-PC inhibits TGF-β/smad2/3 signaling pathway in Caski cells
4. C-PC induced cell cycle G0/G1 arrest by decreasing protein expression levels of Cyclin D1 and p27
Down-regulation of TGF-β/samd2/3 signal pathway can prevent epithelial cells from transforming mesenchymal cells which can induce G0/G1 arrest of the tumor cell cycle.
Read the full study here: C-phycocyanin inhibits epithelial-to-mesenchymal transition in Caski cells
(1) Cervical Health Awareness Month. (2021). National Cervical Cancer Coalition. https://www.nccc-online.org/hpvcervical-cancer/cervical-health-awareness-month/
(2) Key Statistics for Cervical Cancer. (2021). American Cancer Society. https://www.cancer.org/cancer/cervical-cancer/about/key-statistics.html
(3) Cervical cancer. (2021). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/cervical-cancer/symptoms-causes/syc-20352501
(4) Ji, H., Liu, G., Han, J., Zhu, F., Dong, X., & Li, B. (2020). C-phycocyanin inhibits epithelial-to-mesenchymal transition in Caski cells. Cancer cell international, 20, 292. https://doi.org/10.1186/s12935-020-01384-8
(5) Metastasis. (2021). NIH: National Cancer Institute. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/metastasis
(6) Vo, T.-S., Ngo, D.-H., & Kim, S.-K. (2015). Nutritional and Pharmaceutical Properties of Microalgal Spirulina. Handbook of Marine Microalgae: Biotechnology Advances. 299-308. 10.1016/B978-0-12-800776-1.00019-4