Polymorphic microbes: a new emerging hallmark of cancer

A comprehensive review and in silico analysis of the role of survivin (BIRC5) in hepatocellular carcinoma hallmarks: A step toward precision

Hepatocellular carcinoma (HCC) is a complex malignancy driven by the dysregulation of multiple cellular pathways. Survivin, a key member of the inhibitor of apoptosis (IAP) family, plays a central role in HCC tumorigenesis and progression. Despite significant research, a comprehensive understanding of the contributions of survivin to the hallmarks of cancer, its molecular network, and its potential as a therapeutic target remains incomplete. In this review, we integrated bioinformatics analysis with an extensive literature review to provide deeper insights into the role of survivin in HCC. Using bioinformatics tools such as the Human Protein Atlas, GEPIA, STRING, TIMER, and Metascape, we analyzed survivin expression and its functional associations and identified the top 20 coexpressed genes in HCC. These include TK1, SPC25, SGO2, PTTG1, PRR11, PLK1, NCAPH, KPNA2, KIF2C, KIF11, HJURP, GTSE1, FOXM1, CEP55, CENPA, CDCA3, CDC45, CCNB2, CCNB1 and CTD-2510F5.4. Our findings also revealed significant protein-protein interactions among these genes, which were enriched in pathways associated with the FOXM1 oncogenic signaling cascade, and biological processes such as cell cycle regulation, mitotic checkpoints, and diseases such as liver neoplasms. We also discussed the involvement of survivin in key oncogenic pathways, including the PI3K/AKT, WNT/β-catenin, Hippo, and JAK/STAT3 pathways, and its role in modulating cell cycle checkpoints, apoptosis, and autophagy. Furthermore, we explored its interactions with the tumor microenvironment, particularly its impact on immune modulation through myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages, and natural killer cell function in HCC. Additionally, we highlighted its involvement in alkylglycerone phosphate synthase (AGPS)-mediated lipid reprogramming and identified important gaps in the survivin network that warrant further investigation. This review also examined the role of survivin in cancer stemness, inflammation, and virally mediated hepatocarcinogenesis. We evaluated its potential as a diagnostic, prognostic, predictive, and pharmacodynamic biomarker in HCC, emphasizing its relevance in precision medicine. Finally, we summarized emerging survivin-targeted therapeutics and ongoing clinical trials, underscoring the need for novel strategies to effectively target survivin in HCC.

Host-microbe-cancer interactions on-a-chip

The tumor microbiota has emerged as a pivotal contributor to a variety of cancers, impacting disease development, progression, and therapeutic resistance. Due to the complexity of the tumor microenvironment, reproducing the interactions between the microbes, tumor cells, and the immune system remains a great challenge for both in vitro and in vivo studies. To this end, significant progress has been made toward leveraging tumor-on-a-chip model systems to replicate critical hallmarks of the native disease in vitro. These microfluidic platforms offer the ability to mimic essential components of the tumor microenvironment, including controllable fluid flow conditions, manipulable extracellular matrix dynamics, and intricate 3D multi-cellular communication. The primary objective of this review is to discuss recent challenges and advances in engineering host-microbiota and tumor interactions on-a-chip. Ultimately, overcoming these obstacles will help us gain deeper insights into tumor-microbe interactions and enhance avenues for developing more effective cancer therapies.

The Role of Oral Yeasts in the Development and Progression of Oral Squamous Cell Carcinoma: A Scoping Review

The role of oral yeasts in oral squamous cell carcinoma (OSCC) has gained attention due to evidence linking fungal dysbiosis to carcinogenesis. While Candida albicans has been the primary focus, emerging studies highlight the importance of non-Candida species yeast genera. This scoping review synthesises the evidence on the role of oral yeasts, including Candida spp. and non-Candida species, in the development and progression of OSCC. A PRISMA-ScR-guided search was conducted in Medline, Embase, EBM Reviews, and CINAHL. Observational and experimental studies involving humans with OSCC, oral potentially malignant disorders (OPMDs), or oral epithelial dysplasia (OED) were included. This review analysed 75 studies. Research on oral yeast in OSCC has progressed since the 1970s, with advancements in identification techniques-from conventional culture methods to metagenomic sequencing and multi-omics approaches-alongside improved animal and cellular models of OSCC. These methodological advancements have identified notable distinctions in the oral mycobiome between carcinomatous and healthy states. Clinical findings reinforce the hypothesis that oral yeasts, particularly Candida spp., actively contribute to the dysplasia-carcinoma sequence. Emerging evidence suggests that oral yeasts may significantly modulate events contributing to OSCC progression. However, further mechanistic studies and robust clinical evidence are essential to establish causality and clarify their role in OSCC.

Small Biological Fighters Against Cancer: Viruses, Bacteria, Archaea, Fungi, Protozoa, and Microalgae

Despite the progress made in oncological theranostics, cancer remains a global health problem and a leading cause of death worldwide. Multidrug and radiation therapy resistance is an important challenge in cancer treatment. To overcome this great concern in clinical practice, conventional therapies are more and more used in combination with modern approaches to improve the quality of patients' lives. In this review, we emphasize how small biological entities, such as viruses, bacteria, archaea, fungi, protozoans, and microalgae, as well as their related structural compounds and toxins/metabolites/bioactive molecules, can prevent and suppress cancer or regulate malignant initiation, progression, metastasis, and responses to different therapies. All these small biological fighters are free-living or parasitic in nature and, furthermore, viruses, bacteria, archaea, fungi, and protozoans are components of human and animal microbiomes. Recently, polymorphic microbiomes have been recognized as a new emerging hallmark of cancer. Fortunately, there is no limit to the development of novel approaches in cancer biomedicine. Thus, viral vector-based cancer therapies based on genetically engineered viruses, bacteriotherapy, mycotherapy based on anti-cancer fungal bioactive compounds, use of protozoan parasite-derived proteins, nanoarchaeosomes, and microalgae-based microrobots have been more and more used in oncology, promoting biomimetic approaches and biology-inspired strategies to maximize cancer diagnostic and therapy efficiency, leading to an improved patients' quality of life.

Exploiting the gut microbiome for brain tumour treatment

Increasing evidence suggests that the gut microbiome plays a key role in a host of pathological conditions, including cancer. Indeed, the bidirectional communication that occurs between the gut and the brain, known as the 'gut-brain axis,' has recently been implicated in brain tumour pathology. Here, we focus on current research that supports a gut microbiome-brain tumour link with emphasis on high-grade gliomas, the most aggressive of all brain tumours, and the impact on the glioma tumour microenvironment. We discuss the potential use of gut-brain axis signals to improve responses to current and future therapeutic approaches. We highlight that the success of novel treatment strategies may rely on patient-specific microbiome profiles, and these should be considered for personalised treatment approaches.

Post-Translational Modifications of Proteins Orchestrate All Hallmarks of Cancer

Post-translational modifications (PTMs) of proteins dynamically build the buffering and adapting interface between oncogenic mutations and environmental stressors, on the one hand, and cancer cell structure, functioning, and behavior. Aberrant PTMs can be considered as enabling characteristics of cancer as long as they orchestrate all malignant modifications and variability in the proteome of cancer cells, cancer-associated cells, and tumor microenvironment (TME). On the other hand, PTMs of proteins can enhance anticancer mechanisms in the tumoral ecosystem or sustain the beneficial effects of oncologic therapies through degradation or inactivation of carcinogenic proteins or/and activation of tumor-suppressor proteins. In this review, we summarized and analyzed a wide spectrum of PTMs of proteins involved in all regulatory mechanisms that drive tumorigenesis, genetic instability, epigenetic reprogramming, all events of the metastatic cascade, cytoskeleton and extracellular matrix (ECM) remodeling, angiogenesis, immune response, tumor-associated microbiome, and metabolism rewiring as the most important hallmarks of cancer. All cancer hallmarks develop due to PTMs of proteins, which modulate gene transcription, intracellular and extracellular signaling, protein size, activity, stability and localization, trafficking, secretion, intracellular protein degradation or half-life, and protein-protein interactions (PPIs). PTMs associated with cancer can be exploited to better understand the underlying molecular mechanisms of this heterogeneous and chameleonic disease, find new biomarkers of cancer progression and prognosis, personalize oncotherapies, and discover new targets for drug development.

Injecting hope: the potential of intratumoral immunotherapy for locally advanced and metastatic cancer

Despite enormous progress, advanced cancers are still one of the most serious medical problems in current society. Although various agents and therapeutic strategies with anticancer activity are known and used, they often fail to achieve satisfactory long-term patient outcomes and survival. Recently, immunotherapy has shown success in patients by harnessing important interactions between the immune system and cancer. However, many of these therapies lead to frequent side effects when administered systemically, prompting treatment modifications or discontinuation or, in severe cases, fatalities. New therapeutic approaches like intratumoral immunotherapy, characterized by reduced side effects, cost, and systemic toxicity, offer promising prospects for future applications in clinical oncology. In the context of locally advanced or metastatic cancer, combining diverse immunotherapeutic and other treatment strategies targeting multiple cancer hallmarks appears crucial. Such combination therapies hold promise for improving patient outcomes and survival and for promoting a sustained systemic response. This review aims to provide a current overview of immunotherapeutic approaches, specifically focusing on the intratumoral administration of drugs in patients with locally advanced and metastatic cancers. It also explores the integration of intratumoral administration with other modalities to maximize therapeutic response. Additionally, the review summarizes recent advances in intratumoral immunotherapy and discusses novel therapeutic approaches, outlining future directions in the field.

Viewing Native American Cervical Cancer Disparities through the Lens of the Vaginal Microbiome: A Pilot Study

Vaginal dysbiosis is implicated in persistent human papillomavirus (HPV) infection and cervical cancer. Yet, there is a paucity of data on the vaginal microbiome in Native American communities. Here, we aimed to elucidate the relationships between microbiome, HPV, sociodemographic, and behavioral risk factors to better understand an increased cervical cancer risk in Native American women. In this pilot study, we recruited 31 participants (16 Native American and 15 non-Native women) in Northern Arizona and examined vaginal microbiota composition, HPV status, and immune mediators. We also assessed individuals' sociodemographic information and physical, mental, sexual, and reproductive health. Overall, microbiota profiles were dominated by common Lactobacillus species (associated with vaginal health) or a mixture of bacterial vaginosis-associated bacteria. Only 44% of Native women exhibited Lactobacillus dominance, compared with 58% of non-Native women. Women with vaginal dysbiosis also had elevated vaginal pH and were more frequently infected with high-risk HPV. Furthermore, we observed associations of multiple people in a household, lower level of education, and high parity with vaginal dysbiosis and abundance of specific bacterial species. Finally, women with dysbiotic microbiota presented with elevated vaginal levels of proinflammatory cytokines. Altogether, these findings indicate an interplay between HPV, vaginal microbiota, and host defense, which may play a role in the cervical cancer disparity among Native American women. Future longitudinal studies are needed to determine the mechanistic role of vaginal microbiota in HPV persistence in the context of social determinants of health toward the long-term goal of reducing health disparities between non-Hispanic White and Native American populations. Prevention Relevance: Cervical cancer disproportionally affects Native American women. Sociodemographic and behavioral factors might contribute to this disparity via alteration of vaginal microbiota. Here, we show the association between these factors and vaginal dysbiosis and immune activation, which can be implicated in high-risk HPV infection among Native American and other racial/ethnic populations.

Star wars against leukemia: attacking the clones

Leukemia, although most likely starts as a monoclonal genetic/epigenetic anomaly, is a polyclonal disease at manifestation. This polyclonal nature results from ongoing evolutionary changes in the genome/epigenome of leukemia cells to promote their survival and proliferation advantages. We discuss here how genetic and/or epigenetic aberrations alter intracellular microenvironment in individual leukemia clones and how extracellular microenvironment selects the best fitted clones. This dynamic polyclonal composition of leukemia makes designing an effective therapy a challenging task especially because individual leukemia clones often display substantial differences in response to treatment. Here, we discuss novel therapeutic approach employing single cell multiomics to identify and eradicate all individual clones in a patient.

Tumor-Resident Microbiota-Based Risk Model Predicts Neoadjuvant Therapy Response of Locally Advanced Esophageal Squamous Cell Carcinoma Patients

Few predictive biomarkers exist for identifying patients who may benefit from neoadjuvant therapy (NAT). The intratumoral microbial composition is comprehensively profiled to predict the efficacy and prognosis of patients with esophageal squamous cell carcinoma (ESCC) who underwent NAT and curative esophagectomy. Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis is conducted to screen for the most closely related microbiota and develop a microbiota-based risk prediction (MRP) model on the genera of TM7x, Sphingobacterium, and Prevotella. The predictive accuracy and prognostic value of the MRP model across multiple centers are validated. The MRP model demonstrates good predictive accuracy for therapeutic responses in the training, validation, and independent validation sets. The MRP model also predicts disease-free survival (p = 0.00074 in the internal validation set and p = 0.0017 in the independent validation set) and overall survival (p = 0.00023 in the internal validation set and p = 0.11 in the independent validation set) of patients. The MRP-plus model basing on MRP, tumor stage, and tumor size can also predict the patients who can benefit from NAT. In conclusion, the developed MRP and MRP-plus models may function as promising biomarkers and prognostic indicators accessible at the time of diagnosis.

A viable remedy for overcoming resistance to anti-PD-1 immunotherapy: Fecal microbiota transplantation

Anti-PD-1 immunotherapy is a cancer therapy that focuses explicitly on the PD-1 receptor found on the surface of immune cells. This targeted therapeutic strategy is specifically designed to amplify the immune system's innate capacity to detect and subsequently eliminate cells that have become cancerous. Nevertheless, it should be noted that not all patients exhibit a favourable response to this particular therapeutic modality, necessitating the exploration of novel strategies to augment the effectiveness of immunotherapy. Previous studies have shown that fecal microbiota transplantation (FMT) can enhance the efficacy of anti-PD-1 immunotherapy in advanced melanoma patients. To investigate this intriguing possibility further, we turned to PubMed and conducted a comprehensive search for studies that analyzed the interplay between FMT and anti-PD-1 therapy in the context of tumor treatment. Our search criteria were centred around two key phrases: "fecal microbiota transplantation" and "anti-PD-1 therapy." The studies we uncovered all echo a similar sentiment. They pointed towards the potential of FMT to improve the effectiveness of immunotherapy. FMT may enhance the effectiveness of immunotherapy by altering the gut microbiota and boosting the patient's immunological response. Although promising, additional investigation is needed to improve the efficacy of FMT in the context of cancer therapy and attain a comprehensive understanding of the possible advantages and drawbacks associated with this therapeutic strategy.

Case report: Primary CDK4/6 inhibitor and endocrine therapy in locally advanced breast cancer and its effect on gut and intratumoral microbiota

Locally advanced breast cancer poses significant challenges to the multidisciplinary team, in particular with hormone receptor (HR) positive, HER2-negative tumors that classically yield lower pathological complete responses with chemotherapy. The increasingly significant use of CDK 4/6 inhibitors (CDK4/6i) plus endocrine therapy (ET) in different breast cancer settings has led to clinical trials focusing on this strategy as a primary treatment, with promising results. The impact of the microbiota on cancer, and vice-versa, is an emerging topic in oncology. The authors report a clinical case of a postmenopausal female patient with an invasive breast carcinoma of the right breast, Luminal B-like, staged as cT4cN3M0 (IIIB). Since the lesion was considered primarily inoperable, the patient started letrozole and ribociclib. Following 6 months of systemic therapy, the clinical response was significant, and surgery with curative intent was performed. The final staging was ypT3ypN2aM0, R1, and the patient started adjuvant letrozole and radiotherapy. This case provides important insights on primary CDK4/6i plus ET in locally advanced unresectable HR+/HER2- breast cancer and its potential implications in disease management further ahead. The patient's gut microbiota was analyzed throughout the disease course and therapeutic approach, evidencing a shift in gut microbial dominance from Firmicutes to Bacteroidetes and a loss of microbial diversity following 6 months of systemic therapy. The analysis of the intratumoral microbiota from the surgical specimen revealed high microbial dissimilarity between the residual tumor and respective margins.

Propionate reinforces epithelial identity and reduces aggressiveness of lung carcinoma

The epithelial-to-mesenchymal transition (EMT) plays a central role in the development of cancer metastasis and resistance to chemotherapy. However, its pharmacological treatment remains challenging. Here, we used an EMT-focused integrative functional genomic approach and identified an inverse association between short-chain fatty acids (propionate and butanoate) and EMT in non-small cell lung cancer (NSCLC) patients. Remarkably, treatment with propionate in vitro reinforced the epithelial transcriptional program promoting cell-to-cell contact and cell adhesion, while reducing the aggressive and chemo-resistant EMT phenotype in lung cancer cell lines. Propionate treatment also decreased the metastatic potential and limited lymph node spread in both nude mice and a genetic NSCLC mouse model. Further analysis revealed that chromatin remodeling through H3K27 acetylation (mediated by p300) is the mechanism underlying the shift toward an epithelial state upon propionate treatment. The results suggest that propionate administration has therapeutic potential in reducing NSCLC aggressiveness and warrants further clinical testing.

Diet-driven microbiome changes and physical activity in cancer patients

Exploring the role of the gut microbiome in oncology is gaining more attention, mainly due to its ability to shape the immune system in cancer patients. A well-balanced microbial composition forms a symbiotic relationship with the host organism. Mounting evidence supports the potential of modifiable lifestyle factors, such as diet and physical activity, in restoring intestinal dysbiosis related to cancer development and treatment. In this Minireview, we describe the host-microbiome interplay following different dietary patterns, including a high-fat diet, fiber-rich diet, diet rich in rice and beans, Mediterranean diet, ketogenic diet, and physical activity in preclinical findings and clinical settings. According to the results, nutrition is a critical factor influencing the composition of gut microbial communities. Therefore, knowledge about the patient's nutritional status in pre-treatment and treatment becomes crucial for further management. A combination of individualized dietary habits and professional training plans might help to maintain gut homeostasis, potentially improving the response to anti-cancer therapy and the quality of life in cancer survivors. However, a deep understanding of underlying mechanisms and large clinical trials are needed to uncover clinically relevant correlations for personalized treatment approaches leading to better outcomes for cancer patients.

Computational methods and challenges in analyzing intratumoral microbiome data

The human microbiome is intimately related to cancer biology and plays a vital role in the efficacy of cancer treatments, including immunotherapy. Extraordinary evidence has revealed that several microbes influence tumor development through interaction with the host immune system, that is, immuno-oncology-microbiome (IOM). This review focuses on the intratumoral microbiome in IOM and describes the available data and computational methods for discovering biological insights of microbial profiling from host bulk, single-cell, and spatial sequencing data. Critical challenges in data analysis and integration are discussed. Specifically, the microorganisms associated with cancer and cancer treatment in the context of IOM are collected and integrated from the literature. Lastly, we provide our perspectives for future directions in IOM research.

The Gut Microbiome and Metastatic Renal Cell Carcinoma

The introduction of targeted therapy (TT) and immuno-oncology (IO) agents have revolutionized the treatment of metastatic renal cell carcinoma (mRCC). However, despite the significant improvements in survival and clinical response yielded by these agents, a significant percentage of patients still experience progressive disease. Evidence now suggests that microorganisms living in the gut (i.e., the gut microbiome) could be used as a biomarker for response and may also have utility in increasing response to these treatments. In this review, we present an overview of the role of the gut microbiome in cancer and its potential implications in the treatment of mRCC.

Defining the Role of the Gut Microbiome in the Pathogenesis and Treatment of Lymphoid Malignancies

The gut microbiome is increasingly being recognized as an important immunologic environment, with direct links to the host immune system. The scale of the gut microbiome's genomic repertoire extends the capacity of its host's genome by providing additional metabolic output, and the close communication between gut microbiota and mucosal immune cells provides a continued opportunity for immune education. The relationship between the gut microbiome and the host immune system has important implications for oncologic disease, including lymphoma, a malignancy derived from within the immune system itself. In this review, we explore past and recent discoveries describing the role that bacterial populations play in lymphomagenesis, diagnosis, and therapy. We highlight key relationships within the gut microbiome-immune-oncology axis that present exciting opportunities for directed interventions intended to shape the microbiome for therapeutic effect. We conclude with a limited summary of active clinical trials targeting the microbiome in hematologic malignancies, along with future directions on gut microbiome investigations within lymphoid malignancies.