Current development of pancreas transfection in science
The pancreas is one of the vital organs in our body. They are prone to different diseases like diabetes, cancer, and pancreatitis. Some pancreatic diseases cannot be treated with traditional methods. Novel approaches need to be used to overcome these issues. One such method is pancreas transfection. Transfection is defined as that phenomenon in which foreign genes are inserted into any organ or organism through non-viral methods. These non-viral methods include stem cell therapies, ultrasound-mediated gene transfer, electroporation, and microinjection (Eberwine, 2010). The pancreas is a sensitive organ with important bodily functions, therefore minimizing any risk associated with viral gene transfer. Transfection methods are used. Transfection methods are less effective as compared to viral methods. But they have advantages over methods other than viral methods. Transfection methods are also safe as compared to viral methods. Viral methods are unsafe because the viral vector may further exacerbate the condition of the pancreas.
Stem cell-mediated gene therapy is the pancreas’s most common form of transfection method. Stem cells are defined as those cells which have unlimited growth potential. Furthermore, these cells can be further reprogrammed into different types of cells. For example, stem cells can be reprogrammed to become other types of cells like pancreatic cells, skin cells, etc. However, there are different delivery methods for stem cell-mediated gene therapy. One such method is the photochemical internalization (PCI) method. PCI method incorporates endosomes containing drugs or stem cells. These endosomes release the contents based on photochemical signals. The endosomes are guided to the target sites exposed to light and will release the contents when light falls on their surface (Pål Kristian Selbo, 2010).
A study conducted in 2018 by Jieun Han used the PCI method to transfer stem cells coding tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). TRAIL is a protein that causes apoptosis in cancerous tumors. However, TRAIL is not stable for longer durations. Therefore, the first TRAIL was transfected into stem cells in this study. These stem cells were confirmed for TRAIL production. Stem cells approved for TRIAL protein production were transplanted into tumors in murine cancer models. The transplantation site was irradiated with lasers to stimulate the stem cells to release TRAIL proteins into the tumor. Results of this study concluded that TRAIL protein stem cell-mediated gene therapy using the PCI method effectively reduces tumor cells.
Chika Miyagi-Shiohira, et al. 2018 generated induced tissue-specific stem cells (iTS cells) from murine pancreatic cells using a VEE-RF RNA-based synthetic self-replicating vector containing four genes which reduced integration failure. These genes are OCT4, KLF4, SOX2, and GLIS1. These genes are considered essential genes in inducing pluripotency in embryonic stem cells. The iTS cells generated through this method were expressed differently than induced pluripotent cells or traditionally used islets of Langerhans cells. The iTS cells are functionally superior to iPS cells because they are easily generated, and their differentiation is closest to the pancreatic cells.
Moreover, these induced cells are not involved in tumor formation. Tumor formation is a common problem associated with pancreatic transfection through stem cells. The technique used in this study can further be employed to differentiate other iTS cells into tissue-specific pluripotent cells.
In the above study, VEEF-RF RNA-based vector was transfected in murine models. This vector successfully transformed pancreatic cells into iTS cells. These cells were able to produce insulin in greater quantities when compared to normal insulin-producing cells. These cells were extracted and then transplanted subcutaneously into a murine model deficient in insulin-producing cells. Transplanted iTS were able to maintain the normal insulin levels in insulin-deficient models. Moreover, no tumor was observed in transplanted models. These models became healthy at the end of this study.
Nanoparticle-based delivery methods are also employed in pancreatic transfection. Wei Chen 2019 showed that nanoparticles could be used to make pancreatic cancer susceptible to chemotherapeutic drugs. In this study, miR-212 RNA was encoded in nanoparticles. These nanoparticles are then introduced to in-vitro pancreatic cell lines and in-vivo pancreatic cancer disease models. These cell lines and animal models were resistant to doxorubicin chemotherapeutic drugs. However, miR-212 RNA makes cancer susceptible to doxorubicin and results in the complete eradication of cancer. This study concludes that we can use nanoparticles carrying different genes, RNA, etc., which will sensitize cancer to chemotherapeutic drugs.
Apart from stem cells and nanoparticles, direct gene transfer methods are also employed in pancreatic transfection. One such study employed ultrasound-mediated gene transfer. This study was conducted by Chao Zhang et al. in 2021. This study used an ultrasound targetted microbubble destruction (UTMD) mediated method. This method transfers genes with the help of low-frequency ultrasound waves accompanied by small particles encompassing genes of interest. This gene is either inserted as a vector or a stand-alone gene. In this study, type 2 macaque monkey models were treated using UTMD. The monkeys were transfected with glucagon-like peptide 1 (GLP-1) coded in a plasmid-based DNA. GLP-1 gene was selected for its vital role in the cellular differentiation and growth of islets of Langerhans cells. These cells are responsible for maintaining glucose levels by releasing different hormones. GLP-1 gene is also responsible for decreasing the amount of glycosylated red blood cells. The results showed a reduction in type 2 diabetes-associated markers. An increase in the cellular proliferation of beta cells indicates that the pancreas has started to perform its normal function. Low toxicity and reduced blood glucose levels. This study shows that UTMD is a safe method in pancreatic transfection and can be used further in pancreatic studies. More research is needed to determine whether this method is efficient and safe for humans.
In conclusion, studies are conducted on pancreatic transfection with different types of methods for gene delivery. These methods have advantages and disadvantages and are safe for animal models. However, further studies are needed to determine whether these methods are safe for humans or if they are associated with some disadvantages.