miR-199a-3p increases the anti-tumor activity of palbociclib in liver cancer models

Hepatocellular carcinoma (HCC) is the most common type of liver cancer, accounting for about 75% of all cases. It arises from the cells (hepatocytes) that make up the liver tissue. The prevalence of HCC varies depending on geographical location, age, gender, and risk factors. According to the World Health Organization, HCC is the sixth most common cancer worldwide. The treatment options for HCC depend on several factors, including the stage of the cancer, the patient’s overall health, and the underlying liver function.  The survival rate for HCC varies depending on several factors, including the stage of the cancer, the patient’s overall health, and the underlying liver function. According to the American Cancer Society, the 5-year relative survival rate for localized HCC (cancer that has not spread outside the liver) is around 39%. However, for HCC that has spread to other parts of the body (metastatic), the 5-year relative survival rate drops to around 3%. If a new effective treatment for HCC were discovered, it would have a significant impact on the lives of those affected by this disease. Currently, HCC is a challenging cancer to treat, and many patients do not survive for long after diagnosis. Therefore, a new cure would be a major breakthrough in the field of cancer research and would likely have several implications:

Palbociclib is a promising drug that has shown efficacy in the treatment of certain types of breast cancer. It is a type of targeted therapy known as a CDK4/6 inhibitor, which works by blocking the activity of two proteins called cyclin-dependent kinases 4 and 6. These proteins play a role in promoting the growth and division of cancer cells. While palbociclib has been primarily studied and approved for the treatment of hormone receptor-positive, HER2-negative advanced or metastatic breast cancer in postmenopausal women, preclinical studies and early-phase clinical trials have suggested that palbociclib may have potential as a treatment for other types of cancer as well. For example, studies have shown that palbociclib may have efficacy in the treatment of certain types of non-small cell lung cancer (NSCLC), which is the most common type of lung cancer. NSCLC tumors often have mutations in genes involved in the cell cycle, such as CDK4 and CDK6, which makes them potentially sensitive to CDK4/6 inhibitors like palbociclib. Additionally, studies have suggested that palbociclib may have efficacy in the treatment of other types of solid tumors, such as ovarian cancer, head and neck squamous cell carcinoma, and gastrointestinal stromal tumors. In advanced HCC patients, a phase II trial is currently active to determine whether palbociclib can be effective in subjects with inoperable, recurrent/refractory, advanced HCC. Preclinical studies have shown that palbociclib can inhibit tumor growth in these types of cancer, and early-phase clinical trials are currently underway to evaluate the safety and efficacy of palbociclib in these populations.

Herein, Italian researchers from the University of Ferrara: Dr. Elisa Callegari, Dr. Paola Guerriero, Dr. Cristian Bassi, Dr. Lucilla D’Abundo, Professor Antonio Frassoldati, Professor Silvia Sabbioni, and Professor Massimo Negrini in collaboration with Dr. Edi Simoni and Professor Laura Astolfi from the University of Padua and Professor Enrico Maria Silini from University Hospital of Parma investigated whether the efficacy and anti-tumor activity of palbociclib can be enhanced by combining with agents active against AKT such as PI3K/AKT/mTOR inhibitor and they conducted in vitro and in vivo animal studies of HCC disease models. Palbociclib was combined with either selective AKT inhibitors, microRNA-199a-3p or MK-2206 and their activity was tested in HCC cell lines and in the TG221 HCC transgenic mouse model. Their work is currently published in the peer-reviewed journal, Molecular Therapy Nucleic Acids.

A new innovative approach to cancer treatment is the use of miRNA therapy that utilizes small RNA molecules called microRNAs (miRNAs) to target cancer cells. miRNAs are small non-coding RNA molecules that play a critical role in regulating gene expression. In cancer, certain miRNAs are dysregulated, leading to abnormal cell growth and proliferation. miRNA therapy involves the use of synthetic miRNAs to either mimic the function of tumor suppressor miRNAs or inhibit the function of oncogenic miRNAs.

According to the authors, although the palbociclib/MK-2206 combination was highly effective, it was too toxic and could not be tolerated by mice. Consequently, the miR-199a-3p mimics/palbociclib combination induced either a partial or complete regression of tumor lesions and was relatively well tolerated. Additionally, miR-199a-3p loss was characterized by poor outcomes in HCC patients, and it exhibited significant anti-tumor activity after restoration, including improved doxorubicin sensitivity in HCC cells and enhanced chemosensitivity.

After three weeks of treatment, the miR-199a-3p/palbociclib combination produced a significant reduction in the size and number of tumor nodules compared with miR-199a-3p mimics or palbociclib used as single agents. The efficacy of this combination against sorafenib-resistant cells was reported in vitro and in vivo. Furthermore, the combination resulted in a simultaneous reduction of phosphorylation of both AKT and RB1 at the molecular level. The findings suggested that miR-199a-3p can be used as a suitable alternative to improve available therapies for advanced HCC treatment.

In conclusion, a new cure for HCC would have a significant impact on the lives of those affected by this disease. It would improve survival rates, reduce morbidity, lower healthcare costs, increase the quality of life for patients, and open up new research directions in the field of cancer research. The authors successfully demonstrated the efficacy of miR-199a-3p/ palbociclib combination as an anti-HCC treatment approach to overcome sorafenib resistance. The study provided a general strategy for applying miRNA molecules to enhance the anti-tumor efficacy of drugs without adverse toxicities. In a statement to Medicine Innovates, the authors explained their study advance research on developing highly effective drugs for HCC treatment.