The Ultrastructural Analysis of Human Colorectal Cancer Stem Cell-Derived Spheroids and Their Mouse Xenograft Shows That the Same Cells Types Have Different Ratios

Unraveling rosmarinic acid anticancer mechanisms in oral cancer malignant transformation

Oral squamous cell carcinoma (OSCC) is expected to rise ca. 40 % by 2040. Rosmarinic acid (RA) has been recognized for its anticancer properties, although its role in OSCC has been neglected. This work exploits the activity of RA in 2D and 3D models of OSCC cells to compel a roadmap for its anticancer properties. The results demonstrated that RA significantly reduced cell mass and metabolic activity in a dose, time, and cell-type-dependent manner, predominantly in highly-invasive OSCC, without compromising normal mucosa in therapeutic doses. RA decreased mitochondria membrane potential and increased redox state, which was corroborated by pioneering observations on the metabolome landscape of OSCC cells (glutathione reduction and acetate and fumarate release). RA triggered autophagy, upregulating BNIP3 and BCNL1 and downregulating BIRC5. The upregulation of CADM1 and downregulation of VIM, CADM2, SNAIL1, and SOX9 highlighted the modulation of epithelial-mesenchymal transition and the remodeling of the extracellular matrix by the downregulation of MMP-2 and MMP-9. RA interacts with P-glycoprotein with the highest docking score of -6.4 kcal/mol. The HSC-3 cell surface charge decreased after RA treatment (-22.6 ± 0.3 mV vs. -26.3 ± 0.3 mV, p < 0.0001), suggesting a reversion of cell polarity and the impairment of invasion. RA also shrank the growth and the metabolic activity of multicellular tumor spheroids. Its modest protein binding with human saliva sheds light on its administration by the oromucosal route. Overall, this work supports the need for further research on the anticancer potential of RA in OSCC, either in monotherapy, combined with conventional treatments, or conveyed in nanosystems.

High WTAP expression level as a promising biomarker for poor prognosis in colorectal cancer: a pilot study

Colorectal cancer (CRC) is a major public health concern and identifying prognostic molecular biomarkers can help stratify patients based on risk profiles, thus enabling personalized medicine. Epitranscriptomic modifications play a relevant role in controlling gene expression, N6-methyladenosine (m6A) regulators play crucial roles in cancer progression, but their clinical significance in CRC cancer has thus far not been elucidated. Thus, we aimed to examine by immunohistochemical techniques and RT-qPCR, protein levels and RNAs expression of m6A writers (METTL3, WTAP) and eraser (FTO) in a cohort of 10 patients affected by CRC. The patients were followed for 5 years and values of METTL3, WTAP and FTO RNAs in alive vs dead patients were compared. Proteins expression and RNAs expression had a different trend, METTL3, WTAP and FTO proteins' expression showed an increasing trend from non-cancerous adjacent (N) tissue vs carcinoma (CA) tissue G1 stage, and then a decreasing trend from G1 to G2 and G3 stages. The most marked increase was observed in WTAP that, from a 40% of protein expression positivity in N tissue raised to the 81% of positivity in G1 stage K tissue. RNAs expression of METTL3, WTAP and FTO genes in N tissue vs G1 stage CA tissue was significantly different, the analysis and comparison of RNAs values in patient alive after 5 years (0.58±0.04) vs patients dead after 5 years (1.69±0.29) showed that only WTAP values resulted significantly high in dead patients. The fact that WTAP protein expression levels lower while WTAP RNA expression remains high, lets us hypothesize a sort of inhibition of protein expression, but further studies are needed to clarify the mechanism. Although the results suggest a relationship between biological meaning and prognostic utility of WTAP, this prognostic utility must be confirmed by further studies on a larger sample.

Adult IDH Wild-Type Glioblastoma Ultrastructural Investigation Suggests a Possible Correlation between Morphological Biomarkers and Ki-67 Index

Glioblastoma is an aggressive brain tumor with an average life expectancy between 14 and 16 months after diagnosis. The Ki-67 labeling index (LI), a measure of cellular proliferation, is emerging as a prognostic marker in GBM. In this study, we investigated the ultrastructure of glioblastoma tissue from 9 patients with the same molecular profile (adult IDH wild-type glioblastoma, wild-type ATRX, and positive for TP53 expression, GFAP expression, and EGFR overexpression) to find possible ultrastructural features to be used as biomarkers and correlated with the only parameter that differs among our samples, the Ki-67 LI. Our main results were the visualization of the anatomical basis of astrocyte-endothelial cells crosstalk; the ultrastructural in situ imaging of clusters of hyperactivated microglia cells (MsEVs); the ultrastructural in situ imaging of microglia cells storing lipid vesicles (MsLVs); the ultrastructural in situ imaging of neoplastic cells mitophagy (NCsM). The statistical analysis of our data indicated that MsEVs and MsLVs correlate with the Ki-67 LI value. We can thus assume they are good candidates to be considered morphological biomarkers correlating to Ki-67 LI. The role of NCsM instead must be further evaluated. Our study findings demonstrate that by combining ultrastructural characteristics with molecular information, we can discover biomarkers that have the potential to enhance diagnostic precision, aid in treatment decision-making, identify targets for therapy, and enable personalized treatment plans tailored to each patient. However, further research with larger sample sizes is needed to validate these findings and fully utilize the potential of ultrastructural analysis in managing glioblastoma.

Cortical atrophy in chronic subdural hematoma from ultra-structures to physical properties

Several theories have tried to elucidate the mechanisms behind the pathophysiology of chronic subdural hematoma (CSDH). However, this process is complex and remains mostly unknown. In this study we performed a retrospective randomised analysis comparing the cortical atrophy of 190 patients with unilateral CSDH, with 190 healthy controls. To evaluate the extent of cortical atrophy, CT scan images were utilised to develop an index that is the ratio of the maximum diameter sum of 3 cisterns divided by the maximum diameter of the skull at the temporal lobe level. Also, we reported, for the first time, the ultrastructural analyses of the CSDH using a combination of immunohistochemistry methods and transmission electron microscopy techniques. Internal validation was performed to confirm the assessment of the different degrees of cortical atrophy. Relative Cortical Atrophy Index (RCA index) refers to the sum of the maximum diameter of three cisterns (insular cistern, longitudinal cerebral fissure and cerebral sulci greatest) with the temporal bones' greatest internal distance. This index, strongly related to age in healthy controls, is positively correlated to the preoperative and post-operative maximum diameter of hematoma and the midline shift in CSDH patients. On the contrary, it negatively correlates to the Karnofsky Performance Status (KPS). The Area Under the Receiver Operating Characteristics (AUROC) showed that RCA index effectively differentiated cases from controls. Immunohistochemistry analysis showed that the newly formed CD-31 positive microvessels are higher in number than the CD34-positive microvessels in the CSDH inner membrane than in the outer membrane. Ultrastructural observations highlight the presence of a chronic inflammatory state mainly in the CSDH inner membrane. Integrating these results, we have obtained an etiopathogenetic model of CSDH. Cortical atrophy appears to be the triggering factor activating the cascade of transendothelial cellular filtration, inflammation, membrane formation and neovascularisation leading to the CSDH formation.

Three-Dimensional Spheroids for Cancer Research

In vitro cell culture is one of the most widely used tools used today for increasing our understanding of various things such as protein production, mechanisms of drug action, tissue engineering, and overall cellular biology. For the past decades, however, cancer researchers have relied heavily on conventional two-dimensional (2D) monolayer culture techniques to test a variety of aspects of cancer research ranging from the cytotoxic effects of antitumor drugs to the toxicity of diagnostic dyes and contact tracers. However, many promising cancer therapies have either weak or no efficacy in real-life conditions, therefore delaying or stopping altogether their translating to the clinic. This is, in part, due to the reductionist 2D cultures used to test these materials, which lack appropriate cell-cell contacts, have altered signaling, do not represent the natural tumor microenvironment, and have different drug responses, due to their reduced malignant phenotype when compared to real in vivo tumors. With the most recent advances, cancer research has moved into 3D biological investigation. Three-dimensional (3D) cultures of cancer cells not only recapitulate the in vivo environment better than their 2D counterparts, but they have, in recent years, emerged as a relatively low-cost and scientifically accurate methodology for studying cancer. In this chapter, we highlight the importance of 3D culture, specifically 3D spheroid culture, reviewing some key methodologies for forming 3D spheroids, discussing the experimental tools that can be used in conjunction with 3D spheroids and finally their applications in cancer research.

A Different Exosome Secretion Pattern Characterizes Patient-Derived Colorectal Cancer Multicellular Spheroids and Their Mouse Xenografts

Simple Summary

Exosomes have a role in tumorigenesis and metastatic dissemination, their material content and size being associated with poor prognosis of colorectal cancer (CRC). Our work aims to investigate their secretion patterns in CRC stem cells in patient-derived multicellular tumor spheroids (MTSs) and their mouse xenografts, to unveil possible differences in terms of exosome amount, size, and secretion site between in vitro and in vivo models. Our results show that MTSs’ exosome secretion pattern depends on their structural complexity: few-layer spheroids show a lesser exosome secretion, limited to the apical domain of cancer cells; secretion increases in multilayered spheroids and is visible from apical and basolateral cancer cells domains. In xenograft models, exosome secretion occurs from all cancer cell domains, and it is quantitatively greater than that observed in spheroids. The influence of the surrounding environment of non-tumor cells may account for the difference in exosome secretion patterns between spheroids and xenografts.

Abstract

Up-to-date in vitro and in vivo preclinical models expressing the patient-specific cancer lineage responsible for CRC and its metastatic behavior and responsiveness to therapy are needed. Exosomes’ role in tumorigenesis and the metastatic process was demonstrated, and the material content and size of the exosomes are associated with a poor prognosis of CRC. Exosomes are generally imagined after their recovery from blood serum as isolated entities, and our work aims to investigate them “in situ” in their native environment by scanning and transmission electron microscopy to understand their secretion modalities. We studied CRC stem cells in patient-derived multicellular tumor spheroids (MTSs) and in their mouse xenograft to find possible differences in terms of exosome amount, size, and secretion site between in vitro and in vivo models. We observed that MTSs’ exosome secretion patterns depend on their structural complexity: few-layer MTSs show a lesser exosome secretion, limited to the apical domain of cancer cells, secretion increases in multilayered MTSs, and it develops from apical and basolateral cancer cells domains. In xenograft models, exosome secretion occurs from all cancer cell domains, and it is quantitatively greater than that observed in MTSs. This difference in exosome secretion pattern between MTSs and xenografts may be due to the influence of surrounding non-tumor cells.

Zebrafish Patient-Derived Xenograft Model to Predict Treatment Outcomes of Colorectal Cancer Patients

The use of zebrafish embryos for personalized medicine has become increasingly popular. We present a co-clinical trial aiming to evaluate the use of zPDX (zebrafish Patient-Derived Xenografts) in predicting the response to chemotherapy regimens used for colorectal cancer patients. zPDXs are generated by xenografting tumor tissues in two days post-fertilization zebrafish embryos. zPDXs were exposed to chemotherapy regimens (5-FU, FOLFIRI, FOLFOX, FOLFOXIRI) for 48 h. We used a linear mixed effect model to evaluate the zPDX-specific response to treatments showing for 4/36 zPDXs (11%), a statistically significant reduction of tumor size compared to controls. We used the RECIST criteria to compare the outcome of each patient after chemotherapy with the objective response of its own zPDX model. Of the 36 patients enrolled, 8 metastatic colorectal cancer (mCRC), response rate after first-line therapy, and the zPDX chemosensitivity profile were available. Of eight mCRC patients, five achieved a partial response and three had a stable disease. In 6/8 (75%) we registered a concordance between the response of the patient and the outcomes reported in the corresponding zPDX. Our results provide evidence that the zPDX model can reflect the outcome in mCRC patients, opening a new frontier to personalized medicine.