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- All Subjects: cancer research
- Creators: Gao, Weimin
- Creators: German, Adriana
Description
Esophageal adenocarcinoma (EAC) is one of the most lethal and fastest growing cancers in the United States. Its onset is commonly triggered by metaplastic transformation of normal squamous esophageal epithelial cells to Barrett's esophagus (BE) cells in response to acid reflux. BE patients are believed to progress through non-dysplastic metaplasia and increasing grades of dysplasia prior to EAC. Conventional cancer diagnostic tools rely on bulk-cell analyses that are incapable of identifying intratumoral heterogeneity or rare driver cells that play important roles in cancer progression. An improved single-cell method of cancer diagnosis would overcome this challenge by detecting cancer initiating cells before they progress into untreatable stages. In this study, using EAC as a model, we attempted to identify a more effective method of cancer diagnosis. We quantified the single- and bulk-cell mRNA expression of genes that have been proposed to be instrumental in the progression of EAC through BE. Quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) analysis was performed on human primary cells to measure the mRNA expression levels of BE- and EAC-associated genes. Our results showed high levels of heterogeneity of CDX2 and TFF3 at the single-cell resolution in human BE and EAC samples. Additionally, while expression of VEGF is generally low at the bulk-cell level, our results showed that a few, rare cells had significantly higher VEGF expression levels than the majority of cells in the EAC sample. In conclusion, we have affirmed that EAC cancer cells, as well as BE cells, show high levels of heterogeneity. Based on the VEGF gene expression pattern, single-cell analysis could potentially be more effective for identifying rare, but essential cells for cancer progression, which could then be targeted for treatment. Future studies will focus on analyzing human samples from thousands of normal and cancer subjects to validate the use of single-cell profiling in cancer.
ContributorsHaeuser, Kelsey Lynn (Author) / Tran, Thai (Thesis director) / Kelbauskas, Laimonas (Committee member) / Gao, Weimin (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2013-12
Description
Macrostomum lignano is characterized by its elevated regenerative ability conferred by its high percentage of stem cells (the highest recorded for any animal). M. lignano is already used as a model organism for addressing fundamental questions of stem cell biology, aging, regeneration, and reproduction, but not yet cancer.
M. lignano larvae were isolated into separate wells of 24-well plates. After reaching maturity (30 days), the experimental plates were exposed to 5 Gys of X-rays every 4 days for a total of a 25 Gy exposure. We observed phenotypes that may be attributed to the acute effect of irradiation (e.g. blisters) but we recorded two types of phenotypes that may be a result of long-term effects of exposure to radiation. We observed enlarged testis and dark regions/masses that appeared statistically significantly more frequently in the treated animals (Fisher exact test, p=0.0026). Preliminary histological analyses of the enlarged testis suggest a benign testis enlargement due to an aberrant growth of the testes and an accumulation of aberrant spermatozoa. Importantly, we found that, similar to cancer, the dark masses can grow in size over time and the histological analysis confirms that the observed masses are composed of cells completely different from surrounding normal cells. Notably, we observed that those masses can develop and then completely disappear through an observed method of ejection. M. lignano offer the unique possibility to study in vivo cancer development in a simple organism that can easily be cultured in the lab in large numbers.
M. lignano larvae were isolated into separate wells of 24-well plates. After reaching maturity (30 days), the experimental plates were exposed to 5 Gys of X-rays every 4 days for a total of a 25 Gy exposure. We observed phenotypes that may be attributed to the acute effect of irradiation (e.g. blisters) but we recorded two types of phenotypes that may be a result of long-term effects of exposure to radiation. We observed enlarged testis and dark regions/masses that appeared statistically significantly more frequently in the treated animals (Fisher exact test, p=0.0026). Preliminary histological analyses of the enlarged testis suggest a benign testis enlargement due to an aberrant growth of the testes and an accumulation of aberrant spermatozoa. Importantly, we found that, similar to cancer, the dark masses can grow in size over time and the histological analysis confirms that the observed masses are composed of cells completely different from surrounding normal cells. Notably, we observed that those masses can develop and then completely disappear through an observed method of ejection. M. lignano offer the unique possibility to study in vivo cancer development in a simple organism that can easily be cultured in the lab in large numbers.
ContributorsGerman, Adriana (Author) / Fortunato, Angelo (Thesis director) / Maley, Carlo (Committee member) / School of Life Sciences (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05