Recurring Amplification at 11q22.1-q22.2 Locus Plays an Important Role in Lymph Node Metastasis and Radioresistance in OSCC

Hyperbaric oxygen enhances X-ray induced ferroptosis in oral squamous cell carcinoma cells

OBJECTIVE

The objective of this study was to investigate the combined effect of X-ray radiation (IR) and hyperbaric oxygen (HBO) on oral squamous cell carcinoma (OSCC) cells and to explore the possible molecular mechanism.

METHODS

The OSCC cells were treated with or without IR, together with or without HBO co-exposure. Cells were transfected with specific plasmids using Lipofectamine 2000. The cell varieties, apoptosis markers, and ferroptosis markers were determined by using appropriate method. OSCC xenograft mice model was categorized into several subgroups according to the specific treatement. GPX4 expressions were determined by immunohistochemistry (IHC) in OSCC tissues and were tested by ELISA in serums from OSCC patients.

RESULTS

The co-exposure of IR and HBO significantly strengthened the cytotoxicity of IR on SCC15-S cells in ferroptosis-dependent manner. The regulated GPX4/ferroptosis mediated the HBO function on re-sensitizing the radio-resistant OSCC cells to IR. In xenograft mice, co-exposure of IR and HBO can significantly reduce the tumor under IR activation compared with IR alone. Clinical data indicated that high GPX4 levels were associated with poor chemo-radiotherapy outcome.

CONCLUSIONS

HBO could re-sensitize radio-resistant OSCC cells through GPX4/ferroptosis regulation. These results provide a potential therapeutic strategy for clinical radio-resistance.

Identification and validation of prognostic and tumor microenvironment characteristics of necroptosis index and BIRC3 in clear cell renal cell carcinoma

Background

Necroptosis is a form of programmed cell death; it has an important role in tumorigenesis and metastasis. However, details of the regulation and function of necroptosis in clear cell renal cell carcinoma (ccRCC) remain unclear. It is necessary to explore the significance of necroptosis in ccRCC.

Methods

Necroptosis-related clusters were discerned through the application of Consensus Clustering. Based on the TCGA and GEO databases, we identified prognostic necroptosis-related genes (NRGs) with univariate COX regression analysis. The necroptosis-related model was constructed through the utilization of LASSO regression analysis, and the immune properties, tumor mutation burden, and immunotherapy characteristics of the model were assessed using multiple algorithms and datasets. Furthermore, we conducted comprehensive GO, KEGG, and GSVA analyses to probe into the functional aspects of biological pathways. To explore the expression and of hub gene (BIRC3) in different ccRCC cell types and cell lines, single-cell sequencing data was analysed and we performed Quantitative Real-time PCR to detect the expression of BIRC3 in ccRCC cell lines. Function of BIRC3 in ccRCC was assessed through Cell Counting Kit-8 (CCK8) assay (for proliferation), transwell and wound healing assays (for migration and invasion).

Results

Distinct necroptosis-related clusters exhibiting varying prognostic implications, and enrichment pathways were identified in ccRCC. A robust necroptosis-related model formulated based on the expression of six prognostic NRGs, presented substantial predictive capabilities of overall survival and was shown to be related with patients' immune profiles, tumor mutation burden, and response to immunotherapy. Notably, the hub gene BIRC3 was markedly upregulated in both ccRCC tissues and cell lines, and showed significant correlations with immunosuppressive cells, immune checkpoints, and oncogenic pathways. Downregulation of BIRC3 demonstrated a negative regulatory effect on ccRCC cell proliferation migration and invasion.

Conclusion

The necroptosis-related model assumed a pivotal role in determining the prognosis, tumor mutation burden, immunotherapy response, and immune cell infiltration characteristics among ccRCC patients. BIRC3 exhibited significant correlations with the immunosuppressive microenvironment, which highlighted its potential for informing the design of innovative immunotherapies for ccRCC patients.

Replication stress in mammalian embryo development, differentiation, and reprogramming

Duplicating a genome of 3 billion nucleotides is challenged by a variety of obstacles that can cause replication stress and affect the integrity of the genome. Recent studies show that replication fork slowing and stalling is prevalent in early mammalian development, resulting in genome instability and aneuploidy, and constituting a barrier to development in human reproduction. Genome instability resulting from DNA replication stress is a barrier to the cloning of animals and to the reprogramming of differentiated cells to induced pluripotent stem cells, as well as a barrier to cell transformation. Remarkably, the regions most impacted by replication stress are shared in these different cellular contexts, affecting long genes and flanking intergenic areas. In this review we integrate our knowledge of DNA replication stress in mammalian embryos, in programming, and in reprogramming, and we discuss a potential role for fragile sites in sensing replication stress and restricting cell cycle progression in health and disease.

Caspase activation in tumour-infiltrating lymphocytes is associated with lymph node metastasis in oral squamous cell carcinoma

Oral squamous cell carcinomas (OSCCs) are genetically heterogeneous and exhibit diverse stromal and immune microenvironments. Acquired resistance to standard chemo-, radio-, and targeted therapies remains a major hurdle in planning effective treatment modalities for OSCC patients. Since Caspase 8 (CASP8) is frequently mutated in OSCCs, we were interested to explore a potential interaction between tumour-infiltrating lymphocytes (TILs) and CASP8 activation using high-content image analysis of human tumour (n = 32) sections. Despite the lymphocyte-rich tumour microenvironment, we observed lower activation of CASP8 (0-10% of tumour area) and its downstream effector CASP3 (0-6%) in tumours than in normal oral epithelium. Conversely, we found apoptosis was high for all the lymphocyte subtypes examined (38-52% of lymphocytes within tumour islands). Tumours with higher Fas ligand (FasL) expression had a significantly higher proportion of cleaved CASP3/8 positive cytotoxic T cells within the tumour islands (p = 0.05), and this was associated with the presence of lymph node metastatic disease [odds ratio: 1.046, 95% confidence interval (1.002-1.091), p = 0.039]. Our finding of extensive activation of the extrinsic pathway of apoptosis in TILs, together with evidence of higher FasL in CASP8 mutated tumours, may be useful in predicting the course of disease in individual patients. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Potential for reversing miR-634-mediated cytoprotective processes to improve efficacy of chemotherapy against oral squamous cell carcinoma

For advanced oral squamous cell carcinoma (OSCC), increasing sensitivity to chemotherapy is a major challenge in improving treatment outcomes, and targeting cytoprotective processes that lead to the chemotherapy resistance of cancer cells may be therapeutically promising. Tumor-suppressive microRNAs (miRNAs) can target multiple cancer-promoting genes concurrently and are thus expected to be useful seeds for cancer therapeutics. We revealed that miR-634-mediated targeting of multiple cytoprotective process-related genes, including cellular inhibitor of apoptosis protein 1 (cIAP1), can effectively increase cisplatin (CDDP)-induced cytotoxicity and overcome CDDP resistance in OSCC cells. The combination of topical treatment with miR-634 ointment and administration of CDDP was synergistically effective against OSCC tumor growth in a xenograft mouse model. Furthermore, the expression of miR-634 target genes is frequently upregulated in primary OSCC tumors. Our study suggests that reversing miR-634-mediated cytoprotective processes activated in cancer cells is a potentially useful strategy to improve CDDP efficacy against advanced OSCC.

BIRC3 and BIRC5: multi-faceted inhibitors in cancer

BACKGROUND

The evasion from apoptosis is a common strategy adopted by most tumors, and inhibitors of apoptosis proteins (IAPs) are among the most studied molecular and therapeutic targets. BIRC3 (cellular IAP2) and BIRC5 (survivin) are two of the eight members of the human IAPs family. This family is characterized by the presence of the baculoviral IAP repeat (BIR) domains, involved in protein-protein interactions. In addition to the BIR domains, IAPs also contain other important domains like the C-terminal ubiquitin-conjugating (UBC) domain, the caspase recruitment (CARD) domain and the C-terminal Ring zinc-finger (RING) domain.

MAIN BODY

BIRC3 and BIRC5 have been characterized in some solid and hematological tumors and are therapeutic targets for the family of drugs called "Smac mimetics". Many evidences point to the pro-survival and antiapoptotic role of BIRC3 in cancer cells, however, not all the data are consistent and the resulting picture is heterogeneous. For instance, BIRC3 genetic inactivation due to deletions or point mutations is consistently associated to shorter progression free survival and poor prognosis in chronic lymphocytic leukemia patients. BIRC3 inactivation has also been associated to chemoimmunotherapy resistance. On the contrary, the progression from low grade gliomas to high grade gliomas is accompanied by BIRC3 expression increase, which bears relevant prognostic consequences. Due to the relationship between BIRC3, MAP3K14 and the non-canonical NF-kB pathway, BIRC3 inactivation bears consequences also on the tumor cells relying on NF-kB pathway to survive. BIRC5, on the contrary, is commonly considered an anti-apoptotic molecule, promoting cell division and tumor progression and it is widely regarded as potential therapeutic target.

CONCLUSIONS

The present manuscript collects and reviews the most recent literature concerning the role played by BIRC3 and BIRC5 in cancer cells, providing useful information for the choice of the best therapeutic targets.

Mutational drivers of cancer cell migration and invasion

Genomic instability and mutations underlie the hallmarks of cancer-genetic alterations determine cancer cell fate by affecting cell proliferation, apoptosis and immune response, and increasing data show that mutations are involved in metastasis, a crucial event in cancer progression and a life-threatening problem in cancer patients. Invasion is the first step in the metastatic cascade, when tumour cells acquire the ability to move, penetrate into the surrounding tissue and enter lymphatic and blood vessels in order to disseminate. A role for genetic alterations in invasion is not universally accepted, with sceptics arguing that cellular motility is related only to external factors such as hypoxia, chemoattractants and the rigidity of the extracellular matrix. However, increasing evidence shows that mutations might trigger and accelerate the migration and invasion of different types of cancer cells. In this review, we summarise data from published literature on the effect of chromosomal instability and genetic mutations on cancer cell migration and invasion.

Chromosome Abnormalities: New Insights into Their Clinical Significance in Cancer

Chromosomal abnormalities, consisting of numerical and structural chromosome abnormalities, are a common characteristic of cancer. Numerical chromosome abnormalities, mainly including aneuploidy and chromosome instability, are caused by chromosome segregation errors in mitosis, whereas structural chromosome abnormalities are a consequence of DNA damage and comprise focal/arm-level chromosome gain or loss. Recent advances have started to unveil the mechanisms by which chromosomal abnormalities can facilitate tumorigenesis and change the cellular fitness and the expression or function of RNAs and proteins. Accumulating evidence suggests that chromosome abnormalities represent a genomic signature that is linked to cancer prognosis and reaction to chemotherapy and immunotherapy. In this review, we discuss the most recent findings on the role of chromosome abnormalities in tumorigenesis and cancer progression, with a particular emphasis on how aneuploidy and chromosome instability influence cancer therapy and prognosis. We also highlight the distribution and clinical application of the structural chromosome abnormalities in various cancer types. A better understanding of the role of chromosome abnormalities will be beneficial to the development of precision oncology and suggest future directions for the field.

Molecular p-doping in organic liquid crystalline semiconductors: influence of the charge transfer complex on the properties of mesophase and bulk charge transport

We explore the molecular nature of doping in organic semiconductors (OSCs) by employing a liquid crystalline organic semiconductor based on phenyl naphthalene as a model. The mesophase nature of composites that include a charge transfer complex (CTC) between the OSC (8-PNP-O12) and an electron acceptor (F4TCNQ) has been investigated by means of differential scanning calorimetry, polarized optical microscopy and X-ray scattering. Optical and vibrational spectroscopies allow us to explore the characteristics and the amount of charge transfer in the CTC and expose some properties that appear only in the complexed state. We have found this system to exhibit partial charge transfer, which manifests itself in all the phase states of the host 8-PNP-O12, as well as in solution. Due to the lowering of molecular symmetry as a result of the charge transfer, one of the previously IR-only vibrational bands of the nitrile group is found to be now active in the Raman spectrum. We have also made an attempt to further investigate the influence of dopant introduction on the bulk hole mobility of 8-PNP-O12. It is found that the presence of the CTC promotes the hole transport in the Smectic B mesophase, however it seems to have a somewhat negative influence in the less ordered smectic A mesophase. This work aims to establish the link between the inevitable change of molecular geometry that occurs on charge transfer with the results obtained by spectroscopic techniques and electronic charge carrier mobility measurements.