Cell division patterns and chromosomal segregation defects in oral cancer stem cells

The contribution of asymmetric cell division to phenotypic heterogeneity in cancer

Cells have evolved intricate mechanisms for dividing their contents in the most symmetric way during mitosis. However, a small proportion of cell divisions results in asymmetric segregation of cellular components, which leads to differences in the characteristics of daughter cells. Although the classical function of asymmetric cell division (ACD) in the regulation of pluripotency is the generation of one differentiated daughter cell and one self-renewing stem cell, recent evidence suggests that ACD plays a role in other physiological processes. In cancer, tumor heterogeneity can result from the asymmetric segregation of genetic material and other cellular components, resulting in cell-to-cell differences in fitness and response to therapy. Defining the contribution of ACD in generating differences in key features relevant to cancer biology is crucial to advancing our understanding of the causes of tumor heterogeneity and developing strategies to mitigate or counteract it. In this Review, we delve into the occurrence of asymmetric mitosis in cancer cells and consider how ACD contributes to the variability of several phenotypes. By synthesizing the current literature, we explore the molecular mechanisms underlying ACD, the implications of phenotypic heterogeneity in cancer, and the complex interplay between these two phenomena.

The role of mitosis in generating fitness heterogeneity

Cancer cells have heterogeneous fitness, and this heterogeneity stems from genetic and epigenetic sources. Here, we sought to assess the contribution of asymmetric mitosis (AM) and time on the variability of fitness in sister cells. Around one quarter of sisters had differences in fitness, assessed as the intermitotic time (IMT), from 330 to 510 min. Phenotypes related to fitness, such as ERK activity (herein referring to ERK1 and ERK2, also known as MAPK3 and MAPK1, respectively), DNA damage and nuclear morphological phenotypes were also asymmetric at mitosis or turned asymmetric over the course of the cell cycle. The ERK activity of mother cell was found to influence the ERK activity and the IMT of the daughter cells, and cells with ERK asymmetry at mitosis produced more offspring with AMs, suggesting heritability of the AM phenotype for ERK activity. Our findings demonstrate how variabilities in sister cells can be generated, contributing to the phenotype heterogeneities in tumor cells.

Cancer Stem Cell for Tumor Therapy

Simple Summary

Although many methods have been applied in clinical treatment for tumors, they still always show a poor prognosis. Molecule targeted therapy has revolutionized tumor therapy, and a proper target must be found urgently. With a crucial role in tumor development, metastasis and recurrence, cancer stem cells have been found to be a feasible and potential target for tumor therapy. We list the unique biological characteristics of cancer stem cells and summarize the recent strategies to target cancer stem cells for tumor therapy, through which we hope to provide a comprehensive understanding of cancer stem cells and find a better combinational strategy to target cancer stem cells for tumor therapy.

Abstract

Tumors pose a significant threat to human health. Although many methods, such as operations, chemotherapy and radiotherapy, have been proposed to eliminate tumor cells, the results are unsatisfactory. Targeting therapy has shown potential due to its specificity and efficiency. Meanwhile, it has been revealed that cancer stem cells (CSCs) play a crucial role in the genesis, development, metastasis and recurrence of tumors. Thus, it is feasible to inhibit tumors and improve prognosis via targeting CSCs. In this review, we provide a comprehensive understanding of the biological characteristics of CSCs, including mitotic pattern, metabolic phenotype, therapeutic resistance and related mechanisms. Finally, we summarize CSCs targeted strategies, including targeting CSCs surface markers, targeting CSCs related signal pathways, targeting CSC niches, targeting CSC metabolic pathways, inducing differentiation therapy and immunotherapy (tumor vaccine, CAR-T, oncolytic virus, targeting CSCs–immune cell crosstalk and immunity checkpoint inhibitor). We highlight the potential of immunity therapy and its combinational anti-CSC therapies, which are composed of different drugs working in different mechanisms.

Studying the Role of Chromosomal Instability (CIN) in GI Cancers Using Patient-derived Organoids

Chromosomal instability (CIN) is associated with the initiation and progression of gastrointestinal (GI) tract cancers. Cancers of the GI tract are typically characterized by altered chromosome numbers. While the dynamics of CIN have been extensively characterized in 2D monolayer cell cultures derived from GI tumors, the tumor microenvironment and 3D tumor architecture also contribute to the progression of CIN, which is not captured in 2D cell culture systems. To overcome these limitations, self-organizing cellular structures that retain organ-specific 3D architecture, namely organoids, have been derived from various tissues of the GI tract. Organoids derived from normal tissue and patient tumors serve as a useful paradigm to study the crosstalk between tumor cells in the context of a tissue microenvironment and its impact on chromosomal stability. Such a paradigm, therefore, has a considerable advantage over 2D cell culture systems in drug screening and personalized medicine. Here, we review the importance of patient-derived tumor organoids (PDTOs) as a model to study CIN in cancers of the GI tract.

Cancer Stem Cells in Head and Neck Squamous Cell Carcinoma-Treatment Modalities

Head and neck squamous cell carcinoma (HNSCC) belongs to the most frequent cancer subtypes in the world. Mutations due to genetic and chromosomal instability, syndromes such as Fanconi anemia and the Bloom syndrome, environmental risk factors such as tobacco smoking, alcohol and human papillomavirus infection (HPV) subtypes 16,18,31,33,35,52,58 are implicated in its pathogenesis. The HNSCC belongs to the solid tumors of epithelial origin and consists of stromal, inflammatory, cancer cells and most importantly a fraction of them, the cancer stem cells (CSCs). The identification of the CSCs through their biomarkers such as CD44, CD10, CD166, CD133, CD271, ALDH, Oct4, Nanog, Sox2 and Bmi1, the maintenance of their subpopulation through epithelial to mesenchymal transition, the role of HPV infection regarding their prognosis and of their microenvironment regarding their resistance to therapy, all constitute key elements that must be taken thoroughly into consideration in order to develop an effective targeted therapy. There are already therapies in place targeting specific related biomarkers, important biochemical pathways and growth factors. The aim of this literature review is to illustrate the treatment modalities available against the cancer stem cells of head and neck squamous cell carcinoma.

Identification of Key Genes and Prognostic Value Analysis in Hepatocellular Carcinoma by Integrated Bioinformatics Analysis

Emerging evidence indicates that various functional genes with altered expression are involved in the tumor progression of human cancers. This study is aimed at identifying novel key genes that may be used for hepatocellular carcinoma (HCC) diagnosis, prognosis, and targeted therapy. This study included 3 expression profiles (GSE45267, GSE74656, and GSE84402), which were obtained from the Gene Expression Omnibus (GEO). GEO2R was used to analyze the differentially expressed genes (DEGs) between HCC and normal samples. The functional and pathway enrichment analysis was performed by the Database for Annotation, Visualization and Integrated Discovery. A protein-protein interaction (PPI) network of the identified DEGs was constructed using the Search Tool for the Retrieval of Interacting Gene, and hub genes were identified. ONCOMINE and CCLE databases were used to verify the expression of the hub genes in HCC tissues and cells. Kaplan-Meier plotter was used to assess the effects of the hub genes on the overall survival of HCC patients. A total of 99 DEGs were identified from the 3 expression profiles. These DEGs were enriched with functional processes and pathways related to HCC pathogenesis. From the PPI network, 5 hub genes were identified. The expression of the 5 hub genes was all upregulated in HCC tissues and cells compared with the control tissues and cells. Kaplan-Meier survival curves indicated that high expression of cyclin-dependent kinase (CDK1), cyclin B1 (CCNB1), cyclin B2 (CCNB2), MAD2 mitotic arrest deficient-like 1 (MAD2L1), and topoisomerase IIα (TOP2A) predicted poor overall survival in HCC patients (all log-rank P < 0.01). These results revealed that the DEGs may serve as candidate key genes during HCC pathogenesis. The 5 hub genes, including CDK1, CCNB1, CCNB2, MAD2L1, and TOP2A, may serve as promising prognostic biomarkers in HCC.

A case of double-refractory multiple myeloma with both the IgH-MMSET fusion protein and the congenital abnormality t(11;22)

A 67-year-old female was referred to our hospital with a sternal fracture in March 2008. She received a diagnosis of multiple myeloma (MM) BJP-κ type (ISS stage III). G-banding karyotype revealed 46, XX, t(11;22)(q23.3;q11.2) (Hubacek, Gene 592:193-9, 2016), which was later confirmed to be congenital. After repeated rounds of chemotherapy with bortezomib and lenalidomide, she obtained a very good partial response in August 2014, and she was followed up with no treatment. However, she relapsed in February 2016. At that time, fluorescence in situ hybridization identified del(13q) and t(4;14)(p16;q32), which are associated with a poor prognosis. Furthermore, PCR analysis showed that the chromosome 11 breakpoint was at the APOA5/APOA4 locus at 11q23.3, which is associated with malignancy, and that the chromosome 22 breakpoint was at the SEPT5 intron 1 locus, which also plays a role in leukemogenesis through formation of a fusion gene with MLL. Although she was treated with three further lines of therapy, she died from disease progression in August 2017. Synergism between t(11;22) and t(4;14) may have induced the double-refractory phenotype to proteasome inhibitor and lenalidomide, at least during the chemorefractory phase. We present a biological analysis of this case and a review of the literature.

Assessment of cellular and serum proteome from tongue squamous cell carcinoma patient lacking addictive proclivities for tobacco, betel nut, and alcohol: Case study

The intriguing molecular pathways involved in oral carcinogenesis are still ambiguous. The oral squamous cell carcinoma (OSCC) ranks as the most common type constituting more than 90% of the globally diagnosed oral cancers cases. The elevation in the OSCC incidence rate during past 10 years has an alarming impression on human healthcare. The major challenges associated with OSCC include delayed diagnosis, high metastatic rates, and low 5-year survival rates. The present work foundations on reverse genetic strategy and involves the identification of genes showing expressional variability in an OSCC case lacking addictive proclivities for tobacco, betel nut, and/or alcohol, major etiologies. The expression modulations in the identified genes were analyzed in 16 patients comprising oral pre-cancer and cancer histo-pathologies. The genes SCCA1 and KRT1 were found to down regulate while DNAJC13, GIPC2, MRPL17, IG-Vreg, SSFA2, and UPF0415 upregulated in the oral pre-cancer and cancer pathologies, implicating the genes as crucial players in oral carcinogenesis.

Identification, expansion and characterization of cancer cells with stem cell properties from head and neck squamous cell carcinomas

Head and neck squamous cell carcinoma (HNSCC) is a major public health concern. Recent data indicate the presence of cancer stem cells (CSC) in many solid tumors, including HNSCC. Here, we assessed the stem cell (SC) characteristics, including cell surface markers, radioresistance, chromosomal instability, and in vivo tumorigenic capacity of CSC isolated from HNSCC patient specimens. We show that spheroid enrichment of CSC from early and short-term HNSCC cell cultures was associated with increased expression of CD44, CD133, SOX2 and BMI1 compared with normal oral epithelial cells. On immunophenotyping, five of 12 SC/CSC markers were homogenously expressed in all tumor cultures, while one of 12 was negative, four of 12 showed variable expression, and two of the 12 were expressed heterogeneously. We showed that irradiated CSCs survived and retained their self-renewal capacity across different ionizing radiation (IR) regimens. Fluorescence in situ hybridization (FISH) analyses of parental and clonally-derived tumor cells revealed different chromosome copy numbers from cell to cell, suggesting the presence of chromosomal instability in HNSCC CSC. Further, our in vitro and in vivo mouse engraftment studies suggest that CD44+/CD66- is a promising, consistent biomarker combination for HNSCC CSC. Overall, our findings add further evidence to the proposed role of HNSCC CSCs in therapeutic resistance.