Cancer research needs in vitro assays to generate reliable data. In-vitro models produce information by mimicking self-phenotypes as they exist in tissues. Hence, in vitro and in vivo models are crucial for advancing cancer research. In vitro assay development can decipher molecular mechanisms involved in critical events such as metastasis, drug resistance, immune evasion, and tumor growth. Besides, they are crucial for screening and developing anti-cancer drugs. However, only 10% of anti-cancer drugs reach the market shelf.
The primary reason for such slow growth is intolerable toxicity or inefficiency, putting a lot of focus on relevant bioanalytical testing. Hence, the current article discusses in vitro assay development in cancer research. This article may prove helpful for ELISA assay development service providers in conducting in vitro assay development. However, irrespective of the method of choice, robust bioanalytical method development and validation remain critical for delivering reliable and accurate results.
In vitro assay development
Animal models are crucial for progressing cancer research into clinical studies. Often, for reducing complications, costs, and ethical issues such as replacement, refinement, and reduction of animal models, appropriate in vitro assays are vital for maximizing the potential of a drug compound. Today, a monolayer cancer cell culture in 2D conditions is one of the simplest in vitro methods in cancer research. A 2D cell culture method is a low-cost and straightforward approach to in vitro assessments.
However, 2D cultures have some limitations. The primary limitation is that 2D cultures are inadequate preclinical tumor models and fail to address several pathological problems, for example, tumor microenvironment. Additionally, they do not conserve the polarization and original shape of cells and hence affect cell properties such as cell signaling and functions. As 3D cell culture models can more accurately depict tumor microenvironment, cell behavior in these models may be more reflective of cellular responses observed in in-vivo models.
Preclinical models representing environmental factors and in vivo biology are critical for advancing precision medicine in cancer research. Multiple 2D culture approaches are being studied, such as cancer stromal cells and more complex 3D cultures. Researchers can design 3D cultures using different strategies, including scaffold-based cultures, non-scaffold-based cultures, specialized 3D cultures, and hybrid systems.
The source of cancer cells is a critical part of in vitro tumor models. Researchers often opt for commercially available cell lines in in vitro cancer models. Additionally, investigators use the co-culture approach involving two or more types of cells cultured together to represent the tumor microenvironment.
Additionally, multicellular tumor spheroid is another approach employed in 3D in vitro models. Matrix-embedded hanging drop and low attachment plate techniques are used widely to produce such spheroids. Neutralizing cell viability assays can analyze cells in 2D and 3D cultures. However, it is critical to note that despite advances in 3D models, only a minority of researchers use them in in-vitro cancer studies. The data suggests that additional costs and lack of experience are the primary reasons for not using 3D in vitro models in cancer research.