Taxane chemotherapy induces stromal injury that leads to breast cancer dormancy escape

Integrating multi-omics data to identify the role of Aggrephagy-related genes in tumor microenvironment and key tumorigenesis factors of GB from the perspective of single-cell sequencing

This study presents a pioneering exploration into the role of aggrephagy-related genes (ARGs) in glioblastoma (GB), a kind of malignant tumor which is highly invasive and resistant to a series of therapy. Utilizing single-cell sequencing to dissect their influence on the tumor microenvironment (TME) and tumorigenesis. By applying non-negative matrix factorization for dimensionality reduction and clustering of single-cell data, distinct cellular subtypes within the TME influenced by ARGs were identified, uncovering their functions and interactions. The investigation extends to validating the prognostic significance of ARGs and their potential in predicting immunotherapy outcomes. Molecular docking analysis of key ARGs further highlights TUBA1C and UBB as promising therapeutic targets, offering novel insights into GB's complex biology and suggesting a targeted approach for therapy, which is characterized by some crucial pathways in our analysis, including PI3k-akt and TGF-beta pathways. This comprehensive single-cell level examination not only advances our understanding of aggrephagy's role in GB but also proposes new avenues for prognosis and treatment strategies, emphasizing the critical impact of ARGs on the TME and GB progression.

Metabolic landscape of disseminated cancer dormancy

Cancer dormancy is a phenomenon defined by the entry of cancer cells into a reversible quiescent, nonproliferative state, and represents an essential part of the metastatic cascade responsible for cancer recurrence and mortality. Emerging evidence suggests that metabolic reprogramming plays a pivotal role in enabling entry, maintenance, and exit from dormancy in the face of the different environments of the metastatic cascade. Here, we review the current literature to understand the dynamics of metabolism during dormancy, highlighting its fine-tuning by the host micro- and macroenvironment, and put forward the importance of identifying metabolic vulnerabilities of the dormant state as therapeutic targets to eradicate recurrent disease.

Tumor dormancy and relapse: understanding the molecular mechanisms of cancer recurrence

Cancer recurrence, driven by the phenomenon of tumor dormancy, presents a formidable challenge in oncology. Dormant cancer cells have the ability to evade detection and treatment, leading to relapse. This review emphasizes the urgent need to comprehend tumor dormancy and its implications for cancer recurrence. Despite notable advancements, significant gaps remain in our understanding of the mechanisms underlying dormancy and the lack of reliable biomarkers for predicting relapse. This review provides a comprehensive analysis of the cellular, angiogenic, and immunological aspects of dormancy. It highlights the current therapeutic strategies targeting dormant cells, particularly combination therapies and immunotherapies, which hold promise in preventing relapse. By elucidating these mechanisms and proposing innovative research methodologies, this review aims to deepen our understanding of tumor dormancy, ultimately facilitating the development of more effective strategies for preventing cancer recurrence and improving patient outcomes.

Cancer Cells in Sleep Mode: Wake Them to Eliminate or Keep Them Asleep Forever?

Cancer cell dormancy is a critical phase in cancer development, wherein cancer cells exist in a latent state marked by temporary but reversible growth arrest. This dormancy phase contributes to anticancer drug resistance, cancer recurrence, and metastasis. Treatment strategies aimed at cancer dormancy can be categorized into two contradictory approaches: inducing cancer cells into a dormant state or eliminating dormant cells. While the former seeks to establish permanent dormancy, the latter aims at eradicating this small population of dormant cells. In this review, we explore the current advancements in therapeutic methods targeting cancer cell dormancy and discuss future strategies. The concept of cancer cell dormancy has emerged as a promising avenue for novel cancer treatments, holding the potential for breakthroughs in the future.

Cancer treatments as paradoxical catalysts of tumor awakening in the lung

Much of the fatality of tumors is linked to the growth of metastases, which can emerge months to years after apparently successful treatment of primary tumors. Metastases arise from disseminated tumor cells (DTCs), which disperse through the body in a dormant state to seed distant sites. While some DTCs lodge in pre-metastatic niches (PMNs) and rapidly develop into metastases, other DTCs settle in distinct microenvironments that maintain them in a dormant state. Subsequent awakening, induced by changes in the microenvironment of the DTC, causes outgrowth of metastases. Hence, there has been extensive investigation of the factors causing survival and subsequent awakening of DTCs, with the goal of disrupting these processes to decrease cancer lethality. We here provide a detailed overview of recent developments in understanding of the factors controlling dormancy and awakening in the lung, a common site of metastasis for many solid tumors. These factors include dynamic interactions between DTCs and diverse epithelial, mesenchymal, and immune cell populations resident in the lung. Paradoxically, among key triggers for metastatic outgrowth, lung tissue remodeling arising from damage induced by the treatment of primary tumors play a significant role. In addition, growing evidence emphasizes roles for inflammation and aging in opposing the factors that maintain dormancy. Finally, we discuss strategies being developed or employed to reduce the risk of metastatic recurrence.

Cell-cell interactions mediating primary and metastatic breast cancer dormancy

Breast cancer remains one of the leading causes of death in women around the world. A majority of deaths from breast cancer occur due to cancer cells colonizing distant organ sites. When colonizing these distant organ sites, breast cancer cells have been known to enter into a state of dormancy for extended periods of time. However, the mechanisms that promote dormancy as well as dormant-to-proliferative switch are not fully understood. The tumor microenvironment plays a key role in mediating cancer cell phenotype including regulation of the dormant state. In this review, we highlight cell-cell interactions in the tumor microenvironment mediating breast cancer dormancy at the primary and metastatic sites. Specifically, we describe how immune cells from the lymphoid lineage, tumor-associated myeloid lineage cells, and stromal cells of non-hematopoietic origin as well as tissue resident stromal cells impact dormancy vs. proliferation in breast cancer cells as well as the associated mechanisms. In addition, we highlight the importance of developing model systems and the associated considerations that will be critical in unraveling the mechanisms that promote primary and metastatic breast cancer dormancy mediated via cell-cell interactions.

PTX-RPPR, a conjugate of paclitaxel and NRP-1 peptide inhibitor to prevent tumor growth and metastasis

Paclitaxel, a potent anti-tumor drug widely recognized for its therapeutic efficacy, has faced limitations in clinical application due to its poor solubility. The use of Cremophor EL (CrEL) as a cosolvent in paclitaxel injections has been associated with hypersensitivity reactions in some patients. To overcome these challenges, we have developed a novel conjugate by linking a neuropilin-1 targeting peptide, RPPR, to paclitaxel, resulting in PTX-RPPR. This innovative approach has significantly enhanced the solubility of paclitaxel, achieving a 3.8 mg/mL concentration, a remarkable 90-fold increase over the native drug. PTX-RPPR has shown potent anti-tumor activity, inhibiting tumor cell proliferation with an IC50 ranging from 0.26 to 1.64 μM and effectively suppressing migration, invasion, and angiogenesis at a concentration of 75 nM. Notably, in a 4T1 mammary carcinoma model, PTX-RPPR administered at a dose of 0.7 μmol/kg exhibited tumor growth inhibition comparable to that of paclitaxel at a higher dose of 3.5 μmol/kg, with superior efficacy in preventing lung metastasis. Furthermore, PTX-RPPR effectively reduced NRP-1 expression in both tumors and lungs post-treatment. In contrast to paclitaxel formulated with CrEL, PTX-RPPR did not induce IL-6 expression, suggesting a safer profile in terms of immunological response. Characterized by a particle size of 200 nm and a zeta potential of +30 mV, the nano-formulation of PTX-RPPR demonstrated remarkable stability over seven days. This study introduced PTX-RPPR as a promising peptide-drug conjugate that addresses the solubility and hypersensitivity issues associated with paclitaxel, offering a safer therapeutic strategy for cancer treatment.

Gammaherpesvirus Infection Stimulates Lung Tumor-Promoting Inflammation

Lung tumor-promoting environmental exposures and γherpesvirus infections are associated with Type 17 inflammation. To test the effect of γherpesvirus infection in promoting lung tumorigenesis, we infected mutant K-Ras-expressing (K-RasLA1) mice with the murine γherpesvirus MHV68 via oropharyngeal aspiration. After 7 weeks, the infected mice displayed a more than 2-fold increase in lung tumors relative to their K-RasLA1 uninfected littermates. Assessment of cytokines in the lung revealed that expression of Type 17 cytokines (Il-6, Cxcl1, Csf3) peaked at day 7 post-infection. These observations correlated with the post-infection appearance of known immune mediators of tumor promotion via IL-17A in the lungs of tumor-bearing mice. Surprisingly, Cd84, an immune cell marker mRNA, did not increase in MHV68-infected wild-type mice lacking lung tumors. Csf3 and Cxcl1 protein levels increased more in the lungs of infected K-RasLA1 mice relative to infected wild-type littermates. Flow cytometric and transcriptomic analyses indicated that the infected K-RasLA1 mice had increased Ly6Gdim/Ly6Chi immune cells in the lung relative to levels seen in uninfected control K-RasLA1 mice. Selective methylation of adenosines (m6A modification) in immune-cell-enriched mRNAs appeared to correlate with inflammatory infiltrates in the lung. These observations implicate γherpesvirus infection in lung tumor promotion and selective accumulation of immune cells in the lung that appears to be associated with m6A modification of mRNAs in those cells.

Deciphering Dormant Cells of Lung Adenocarcinoma: Prognostic Insights from O-glycosylation-Related Tumor Dormancy Genes Using Machine Learning

Lung adenocarcinoma (LUAD) poses significant challenges due to its complex biological characteristics and high recurrence rate. The high recurrence rate of LUAD is closely associated with cellular dormancy, which enhances resistance to chemotherapy and evasion of immune cell destruction. Using single-cell RNA sequencing (scRNA-seq) data from LUAD patients, we categorized the cells into two subclusters: dormant and active cells. Utilizing high-density Weighted Gene Co-expression Network Analysis (hdWGCNA) and pseudo-time cell trajectory, aberrant expression of genes involved in protein O-glycosylation was detected in dormant cells, suggesting a crucial role for O-glycosylation in maintaining the dormant state. Intercellular communication analysis highlighted the interaction between fibroblasts and dormant cells, where the Insulin-like Growth Factor (IGF) signaling pathway regulated by O-glycosylation was crucial. By employing Gene Set Variation Analysis (GSVA) and machine learning, a risk score model was developed using hub genes, which showed high accuracy in determining LUAD prognosis. The model also demonstrated robust performance on the training dataset and excellent predictive capability, providing a reliable basis for predicting patient clinical outcomes. The group with a higher risk score exhibited a propensity for adverse outcomes in the tumor microenvironment (TME) and tumor mutational burden (TMB). Additionally, the 50% inhibitory concentration (IC50) values for chemotherapy exhibited significant variations among the different risk groups. In vitro experiments demonstrated that EFNB2, PTTG1IP, and TNFRSF11A were upregulated in dormant tumor cells, which also contributed greatly to the diagnosis of LUAD. In conclusion, this study highlighted the crucial role of O-glycosylation in the dormancy state of LUAD tumors and developed a predictive model for the prognosis of LUAD patients.

Patient-Derived Organoids as Therapy Screening Platforms in Cancer Patients

Patient-derived organoids (PDOs) developed ex vivo and in vitro are increasingly used for therapeutic screening. They provide a more physiologically relevant model for drug discovery and development compared to traditional cell lines. However, several challenges remain to be addressed to fully realize the potential of PDOs in therapeutic screening. This paper summarizes recent advancements in PDO development and the enhancement of PDO culture models. This is achieved by leveraging materials engineering and microfabrication technologies, including organs-on-a-chip and droplet microfluidics. Additionally, this work discusses the application of PDOs in therapy screening to meet diverse requirements and overcome bottlenecks in cancer treatment. Furthermore, this work introduces tools for data processing and analysis of organoids, along with their microenvironment. These tools aim to achieve enhanced readouts. Finally, this work explores the challenges and future perspectives of using PDOs in drug development and personalized screening for cancer patients.

Respiratory viral infection promotes the awakening and outgrowth of dormant metastatic breast cancer cells in lungs

Breast cancer is the second most common cancer globally. Most deaths from breast cancer are due to metastatic disease which often follows long periods of clinical dormancy1. Understanding the mechanisms that disrupt the quiescence of dormant disseminated cancer cells (DCC) is crucial for addressing metastatic progression. Infection with respiratory viruses (e.g. influenza or SARS-CoV-2) is common and triggers an inflammatory response locally and systemically2,3. Here we show that influenza virus infection leads to loss of the pro-dormancy mesenchymal phenotype in breast DCC in the lung, causing DCC proliferation within days of infection, and a greater than 100-fold expansion of carcinoma cells into metastatic lesions within two weeks. Such DCC phenotypic change and expansion is interleukin-6 (IL-6)-dependent. We further show that CD4 T cells are required for the maintenance of pulmonary metastatic burden post-influenza virus infection, in part through attenuation of CD8 cell responses in the lungs. Single-cell RNA-seq analyses reveal DCC-dependent impairment of T-cell activation in the lungs of infected mice. SARS-CoV-2 infected mice also showed increased breast DCC expansion in lungs post-infection. Expanding our findings to human observational data, we observed that cancer survivors contracting a SARS-CoV-2 infection have substantially increased risks of lung metastatic progression and cancer-related death compared to cancer survivors who did not. These discoveries underscore the significant impact of respiratory viral infections on the resurgence of metastatic cancer, offering novel insights into the interconnection between infectious diseases and cancer metastasis.

Dormancy of cutaneous melanoma

Many cancer-related deaths including melanoma result from metastases that develop months or years after the initial cancer therapy. Even the most effective drugs and immune therapies rarely eradicate all tumor cells. Instead, they strongly reduce cancer burden, permitting dormant cancer cells to persist in niches, where they establish a cellular homeostasis with their host without causing clinical symptoms. Dormant cancers respond poorly to most drugs and therapies since they do not proliferate and hide in niches. It therefore remains a major challenge to develop novel therapies for dormant cancers. In this review we focus on the mechanisms regulating the initiation of cutaneous melanoma dormancy as well as those which are involved in reawakening of dormant cutaneous melanoma cells. In recent years the role of neutrophils and niche components in reawakening of melanoma cells came into focus and indicate possible future therapeutic applications. Sophisticated in vitro and in vivo melanoma dormancy models are needed to make progress in this field and are discussed.

"Moderate" adjuvant chemotherapy-induced leukopenia is beneficial for survival of patients with early breast cancer: a retrospective study

BACKGROUND

The association between chemotherapy-induced leukopenia (CIL) and survival for patients with early breast cancer (EBC) is not known. We investigated the relationship between different grades of CIL and survival in patients with EBC receiving adjuvant chemotherapy.

METHODS

A total of 442 patients with EBC receiving a regimen containing an anthracycline (A) and taxane (T) were included into our analysis. Survival analyses were undertaken using Kaplan-Meier curves. The P-value was calculated using the log rank test. Subgroup analysis was conducted to investigate the correlation of CIL grade and survival based on the clinicopathological characteristics of patients. Afterwards, univariate and multivariate analyses screened out independent prognostic factors to construct a prognostic model, the robustness of which was verified.

RESULTS

Patients with EBC who experienced grade 2-4 ("moderate" and "severe") CIL were associated with longer overall survival (OS) than those with grade 0-1 (mild) CIL (P = 0.021). Compared with patients with mild CIL, OS was longer in patients with severe CIL (P = 0.029). Patients who suffered from moderate CIL tended to have longer OS than those with mild CIL (P = 0.082). Nevertheless, there was no distinguishable difference in OS between moderate- or severe-CIL groups. Subgroup analysis revealed that patients with moderate CIL had longer OS than those with mild CIL among patients who were premenstrual, or with human epidermal growth factor receptor 2-positive (HER2+), > 3 lymph nodes with metastases, a tumor diameter > 5 cm. A prognostic model based on menstrual status, N stage, and CIL grade showed satisfactory robustness.

CONCLUSION

The grade of CIL was strongly associated with the prognosis among patients with EBC who received a regimen containing both anthracyclines and taxanes. Patients with a "moderate" CIL grade tended to have better survival outcomes.

Wounding the stroma: Docetaxel's role in dormant breast cancer escape

The mechanistic underpinnings of breast cancer recurrence following periods of dormancy are largely undetermined. A new study in PLOS Biology reveals that docetaxel-induced injury of tumour stromal cells stimulates the release of cytokines that support dormancy escape of breast cancer cells.