Heatmap of lung cancer tissue section depicting number of CD3+ cells as a function of distance into the tumor.

In the United States lung cancer accounts for approximately 140,000 deaths annually and is the third most common cancer. Lung cancer is divided into two main types; small cell lung cancer and the more common non-small cell lung cancer of which lung adenocarcinoma is a subtype and accounts for approximately 50% of all lung cancers. Lung adenocarcinomas (LADC) are particularly difficult to treat, likely due to their heterogenous nature. The majority of LADCs consist of multiple histological subtypes, which can include lepidic, papillary, acinar, micropapillary, and solid. Attempts to understand the formation of this histological heterogeneity indicated no direct relationship between the heterogeneity and specific genetic alterations leading researchers to explore tumor environment as a possible factor.

TGFβ Signaling Activated by Cancer-Associated Fibroblasts Determines the Histological Signature of Lung Adenocarcinoma

In a study entitled, “TGFβ Signaling Activated by Cancer-Associated Fibroblasts Determines the Histological Signature of Lung Adenocarcinoma” researchers explored the influence of the tumor microenvironment on the development of histological subtypes. Both in vivo and in vitro culture of tumor cells were assessed. The in vivo placement of A549 tumors in immunodeficient mice showed distinctive histological features based on placement location within the mouse. To lend further credence to the idea that microenvironment plays a role in cell phenotype, solid- and acinar-typed tumors were removed and reinjected into different regions in mice where transitions from solid-to-acinar (SAT) or from acinar-to-solid (AST) were observed. The researchers then focused on the acinar-type tumors which have a stromal cell-type component, these cancer-associated fibroblasts were isolated, immortalized and used as a component of in vitro work to better understand the cellular mechanisms that underlie the cell subtype transitions.

The in vitro work examined three lung cancer cell lines (A459, Calu-3 and NCI-H292) and utilized the Visikol HISTO tissue-clearing technique for immunofluorescent labeling and clearing of tumor colonies. The lung cancer cells were cultured alone or co-cultured with cancer-associated fibroblasts (CAFs) to better elucidate the role of CAFs in formation of the acinar cell subtype. All three co-culture models revealed gland-like structures compared to models with cancer cells alone indicating SAT induction in the co-culture model. Additional analysis via RNA-sequencing was performed to further delve into the molecular mechanisms behind this phenomenon. Gene expression analysis showed increased levels of genes related to the TGFβ signaling pathway. Using this information, the in vitro co-culture model using CAFs and A549s were treated with siRNA or inhibitors related to TGFβ signaling and both methods showed decreases in acinar formation indicating a key role of TGFβ signaling in the induction of the acinar subtype through SAT. A better understanding of tumor heterogeneity in lung adenocarcinomas is crucial to the development of effective therapeutics and diagnostic criteria and this research paves the way for a more focused approach to targeting specific LADC subtypes.

As a leader in advanced cell culture and imaging, Visikol offers products and services can be used to evaluate cancer progression and therapeutics. Reach out today to learn more about how Visikol can help you drive science forward!

With the increased adoption of holistic health approaches and a stronger consciousness of how the environment impacts our health, an important application of in vitro studies arises. A growing population has become concerned with how extraneous chemicals interrupt endocrine function, and recent advances in cell culture techniques allow researchers to effectively investigate this question. Visikol is a leader in the cell culture industry, utilizing patented clearing technologies and robust 3D models to evaluate the functioning of major organ systems in both healthy and diseased states. One of the body’s most vital systems – the hypothalamic-pituitary-thyroid (HPT) axis – is of particular research interest when it comes to endocrine perturbations because it is fundamental to metabolic equilibrium, growth, and cognitive development.

Plant protection products (PPPs) are particularly prevalent environmental stressors, but the extent to which they interrupt thyroid hormones (TH) is a question that remains for regulatory authorities.

The Method

In a recent publication entitled, “A Microfluidic Thyroid-Liver Platform to Assess Chemical Safety in Humans,” researchers investigated human-relevant interferences of thyroid gland function through the HPT axis – or more specifically, TH catabolism through hepatic enzyme induction. To address the limitations of standard human in-vitro assays, researchers utilized human 3D thyroid and liver organoids on a micro physiological organ chip to evaluate the effects of methimazole (a reference thyroid peroxidase (TPO) inhibitor) over the course of 21 days. With the help of Visikol’s HISTO-M®, samples were cleared to allow for characterization of 3D thyroid model morphology and morphological changes, cAMP accumulation, thyroid hormone secretion, and TPO inhibition. Additional characterization was performed on the liver spheroids to understand TH catabolism, glucuronidated and sulfated thyroxine (gT4/sT4) metabolite formation, and activation of nuclear receptors. Lastly, the functionality of these two 3D models together was assessed on a perfused multi-organ chip platform (the Chip2) to simulate the in vivo interaction between these two organ systems.

Overall, 3D cell culture models allow us to assess the human relevance of safety-related findings in animal models with respect to thyroid toxicity. This research is essential to the development of new PPPs and represents scientifically informed advancement toward a safer, healthier environment. Visikol’s attention to the development of highly useful 3D models is an essential element not only to this research but also to our understanding of how complex organ systems work. Please reach out to explore what Visikol can do for you.