Relationship between tRNA-derived fragments and human cancers.

tRNA-derived fragments, a class of small noncoding RNAs (sncRNAs), have been identified in numerous studies in recent years. tRNA-derived fragments are classified into two main groups, including tRNA halves (tiRNAs) and tRNA-derived small RNA fragments (tRFs), according to different cleavage positions of the precursor or mature tRNAs. Instead of random tRNA degradation debris, a growing body of evidence has shown that tRNA-derived fragments are precise products of specific tRNA modifications and play important roles in biological activities, such as regulating protein translation, affecting gene expression, and altering immune signaling. Recently, the relations between tRNA-derived fragments and the occurrence of human diseases, especially cancers, have generated wide interest. It has been demonstrated that tRNA-derived fragments are involved in cancer cell proliferation, metastasis, progression and survival. In this review, we will describe the biogenesis of tRNA-derived fragments, the distinct expression and function of tRNA-derived fragments in the development of cancers, and their emerging roles as diagnostic and prognostic biomarkers and precise targets of future treatments.

An Imbalance in Histone Modifiers Induces tRNA-Cys-GCA Overexpression and tRF-27 Accumulation by Attenuating Promoter H3K27me3 in Primary Trastuzumab-Resistant Breast Cancer.

tRNA-derived fragments (tRFs) play crucial roles in cancer progression. Among them, tRF-27 has been identified as a key factor in promoting naïve trastuzumab resistance in HER2-positive breast cancer. However, the origin of tRF-27 remains uncertain. In this study, we propose that the upregulated expression of specific cysteine tRNAs may lead to the increased accumulation of tRF-27 in trastuzumab-resistant JIMT1 cells. Mechanistically, the reduced inhibitory H3K27me3 modification at the promoter regions of tRF-27-related tRNA genes in JIMT1 cells, potentially resulting from decreased EZH2 and increased KDM6A activity, may be a critical factor stimulating the transcriptional activity of these tRNA genes. Our research offers fresh insights into the mechanisms underlying elevated tRF-27 levels in trastuzumab-resistant breast cancer cells and suggests potential strategies to mitigate trastuzumab resistance in clinical treatments.

The war between the immune system and the tumor - using immune biomarkers as tracers.

Nowadays, immunotherapy is one of the most promising anti-tumor therapeutic strategy. Specifically, immune-related targets can be used to predict the efficacy and side effects of immunotherapy and monitor the tumor immune response. In the past few decades, increasing numbers of novel immune biomarkers have been found to participate in certain links of the tumor immunity to contribute to the formation of immunosuppression and have entered clinical trials. Here, we systematically reviewed the oncogenesis and progression of cancer in the view of anti-tumor immunity, particularly in terms of tumor antigen expression (related to tumor immunogenicity) and tumor innate immunity to complement the cancer-immune cycle. From the perspective of integrated management of chronic cancer, we also appraised emerging factors affecting tumor immunity (including metabolic, microbial, and exercise-related markers). We finally summarized the clinical studies and applications based on immune biomarkers. Overall, immune biomarkers participate in promoting the development of more precise and individualized immunotherapy by predicting, monitoring, and regulating tumor immune response. Therefore, targeting immune biomarkers may lead to the development of innovative clinical applications.

Unveiling Alterations of Epigenetic Modifications and Chromatin Architecture Leading to Lipid Metabolic Reprogramming during the Evolutionary Trastuzumab Adaptation of HER2-Positive Breast Cancer.

Secondary trastuzumab resistance represents an evolutionary adaptation of HER2-positive breast cancer during anti-HER2 treatment. Most current studies have tended to prioritize HER2 and its associated signaling pathways, often overlooking broader but seemingly less relevant cellular processes, along with their associated genetic and epigenetic mechanisms. Here, transcriptome data is not only characterized but also examined epigenomic and 3D genome architecture information in both trastuzumab-sensitive and secondary-resistant breast cancer cells. The findings reveal that the global metabolic reprogramming associated with trastuzumab resistance may stem from genome-wide alterations in both histone modifications and chromatin structure. Specifically, the transcriptional activities of key genes involved in lipid metabolism appear to be regulated by variant promoter H3K27me3 and H3K4me3 modifications, as well as promoter-enhancer interactions. These discoveries offer valuable insights into how cancer cells adapt to anti-tumor drugs and have the potential to impact future diagnostic and treatment strategies.

Tyrosine kinase inhibitors in HER2-positive metastatic breast cancer with trastuzumab emtansine resistance: insights from a multicenter retrospective real-world study.

The use of trastuzumab emtansine (T-DM1) has revealed significant efficacy in HER2-positive metastatic breast cancer (MBC). However, optimal therapeutic strategies following T-DM1 failure remain a subject of debate in clinical practice. In this multicenter, retrospective, real-world study, we sought to examine the effectiveness and safety of tyrosine kinase inhibitors (TKIs) as a therapeutic strategy in HER2-positive MBC who developed T-DM1 resistance. Between September 2018 and December 2022, 66 patients were enrolled. The median progression-free survival of TKIs-based therapy was 10.1 months (95% CI, 4.7-15.6). Objective response rate and clinical benefit rate were 18.2 and 66.7%, respectively. TKIs-based therapy demonstrated better effectiveness in patients who had previously derived benefit from T-DM1 and featured acquired resistance to trastuzumab. The most common adverse events were diarrhea (36, 54.5%), hand-foot syndrome (31, 47.0%), and leucopenia (30, 45.5%). In conclusion, TKIs-based therapy showed promising effectiveness and safety in HER2-positive MBC patients after T-DM1 failure.

Exosome-Transmitted tRF-16-K8J7K1B Promotes Tamoxifen Resistance by Reducing Drug-Induced Cell Apoptosis in Breast Cancer.

Tamoxifen resistance remains a challenge in hormone receptor-positive (HR+) breast cancer. Recent evidence suggests that transfer ribonucleic acid (tRNA)-derived fragments play pivotal roles in the occurrence and development of various tumors. However, the relationship between tRNA-derived fragments and tamoxifen resistance remains unclear. In this study, we found that the expression of tRF-16-K8J7K1B was upregulated in tamoxifen-resistant cells in comparison with tamoxifen-sensitive cells. Higher levels of tRF-16-K8J7K1B were associated with shorter disease-free survival in HR+ breast cancer. Overexpression of tRF-16-K8J7K1B promotes tamoxifen resistance. Moreover, extracellular tRF-16-K8J7K1B could be packaged into exosomes and could disseminate tamoxifen resistance to recipient cells. Mechanistically, exosomal tRF-16-K8J7K1B downregulates the expression of apoptosis-related proteins, such as caspase 3 and poly (ADP-ribose) polymerase, by targeting tumor necrosis factor-related apoptosis-inducing ligand in receptor cells, thereby reducing drug-induced cell apoptosis. Therapeutically, the inhibition of exosomal tRF-16-K8J7K1B increases the sensitivity of breast cancer cells to tamoxifen in vivo. These data demonstrate that exosomal tRF-16-K8J7K1B may be a novel therapeutic target to overcome tamoxifen resistance in HR+ breast cancer.

The prognostic value of MKL1 in predicting breast cancer immune infiltrates and chemosensitivity.

Megakaryocytic leukemia 1 (MKL1) acts as a transcription factor in the regulation of the immune system and is associated with cancer biology. However, its function in the infiltrating immune cells in breast cancer has not been explored. Our study aimed to analyze the expression of MKL1 in The Cancer Genome Atlas (TCGA) breast cancer dataset. The aim of this study was to evaluate the correlations between MKL1 expression, infiltrating immune cells, and immune control genes. Enriched signaling pathways and drug sensitivity analyses were also performed. Our results indicate that high MKL1 expression could predict better survival in breast cancer patients. MKL1 expression was associated with the expression and function of different immune cells, including T cells, B cells, natural killer (NK) cells, macrophages, neutrophils and dendritic cells (DCs). The chromatin modifying enzymes, cellular senescence, epigenetic regulation of gene expression, estrogen-dependent gene expression, and chromosome maintenance were differentially enriched in MKL1 low expression phenotype. Patients in the high MKL1 expression group showed sensitivity to paclitaxel, while those in the low expression group showed potential sensitivity for cisplatin and docetaxel. In conclusion, MKL1 might act as a potential biomarker of prognostic value for immune infiltration and drug sensitivity in breast cancer.

Anlotinib for the Treatment of Multiple Recurrent Lumbar and Sacral Cord Hemangioblastomas: A Case Report.

Background: Hemangioblastoma (HB) is a rare and highly vascularized tumor that originates from the central nervous system as well as other part of the body. They can appear sporadically or as part of von Hippel-Lindau (VHL) disease, a rare hereditary cancer syndrome. Although surgery can cure the majority of HBs, the disease shows a treatment-refractory challenge upon recurrence. HBs express a high amount of vascular endothelial growth factor (VEGF) which is responsible for angiogenesis and subsequently tumor progression. Anti-angiogenic treatment like bevacizumab has showed effect on HB, so we hypothesized that anlotinib could trigger HB regression via its inhibitory effect on VEGF. Case Presentation: We will share our experience in treating a 62-year-old woman with multiple recurrent lumbar and sacral cord HBs. She was treated with anlotinib (8mg qd d1-14, q3w) for three months and her follow up radiological examination demonstrated marked tumor regression which was evaluated as having partial response pursuant to RECIST 1.1 system. She is currently still receiving treatment of anlotinib orally and the lesions continuously reduced. Conclusion: We have reported that anlotinib can cause significant radiographic response in a patient with multiple recurrent lumbar and sacral cord HBs for the first time. This might enable a novel therapeutic approach for patients with multiple recurrent HB or those with multiple lesions such as in VHL disease which are difficult to resect surgically.

Treatment with pyrotinib-based therapy in lapatinib-resistant HER2-positive metastatic breast cancer: a multicenter real-world study.

Background: Tyrosine kinase inhibitors (TKIs) are effective for treating human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. However, therapies subsequent to TKI progression remain controversial, and effective treatments for TKI resistance are urgently needed. We evaluate the practice of exchange of TKIs, which involves treatment with a different TKI following prior TKI failure. Specifically, this study investigated the efficacy of pyrotinib-based therapy in lapatinib-resistant HER2-positive metastatic breast cancer (NCT04899128). Methods: This real-world study included 76 patients diagnosed with HER2-positive metastatic breast cancer who received pyrotinib-based therapy after lapatinib progression at four Chinese institutions between August 2018 and March 2020. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR), and toxicity profiles were reported. Results: All patients received pyrotinib-based therapy in two or later line therapy. The median PFS was 8.0 months (95% CI 5.1-10.9). OS has not reached. The ORR and CBR were 17.1% and 60.5%, respectively. The median PFS was 7.1 months (95% CI 5.633-8.567) and intracranial ORR was 42.9% in patients who had brain metastasis (n = 14). Patients who benefited from lapatinib ⩾ 6.0 months prior exhibited a longer PFS (10.6 versus 6.0 months, p = 0.034, stratified hazard ratio (HR) 0.534, 95% CI 0.293-0.975). The most common adverse effects were diarrhea (n = 34, 44.7%) and hand-foot syndrome (n = 10, 13.2%). Conclusion: Pyrotinib-based therapy has the potential to improve survival in patients with lapatinib-resistant HER2-positive metastatic breast cancer, including those with brain metastases. Pyrotinib could provide a clinically significant increase in PFS for patients who benefited from prior lapatinib.

A positive feedback loop: RAD18-YAP-TGF-ß between triple-negative breast cancer and macrophages regulates cancer stemness and progression.

As a key regulator of the DNA translesion synthesis (TLS) pathway, RAD18 is error-prone and contributes to the accumulation of DNA mutations. Our previous study showed that it plays an essential role in the progression of multiple tumors. However, the mechanism through which RAD18 influences triple-negative breast cancer (TNBC), especially the interaction between tumor cells and the tumor microenvironment, remains elusive. In this study, we showed that RAD18 expression is markedly higher in patients with high T stage TNBC and inversely correlated with prognosis. High expression of RAD18 facilitated a highly stem-cell phenotype through the Hippo/YAP pathway, which supports the proliferation of TNBC. In addition, the cytokine byproduct TGF-ß activates macrophages to have an M2-like tumor-associated macrophage (TAM) phenotype. Reciprocally, TGF-ß from TAMs activated RAD18 in TNBC to enhance tumor stemness, forming a positive feedback loop. Inhibition of YAP or TGF-ß breaks this loop and suppresses cancer stemness and proliferation In nude mice, RAD18 promoted subcutaneous transplanted tumor growth and M2-type TAM recruitment. Collectively, the RAD18-YAP-TGF-ß loop is essential for the promotion of the stemness phenotype by TNBC and could be a potential therapeutic target for TNBC.

Nonmetastatic breast cancer patients subsequently developing second primary malignancy: A population-based study.

BACKGROUND: With life span extending, breast cancer (BC) survivors may face the possibility of developing second primary cancer (SPC) and considerably shorten survivorship. However, little is known about multiple primary cancer (MPC) patients with nonmetastatic breast cancer as a first primary malignancy (BCFPM). METHODS: Here, we retrospectively analyzed data on cancer survivors with BCFPM diagnosed between 2010 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. The prognostic factors for breast cancer-specific survival (BCSS) were ascertained by the stepwise regression analysis and a competing risk model, and were integrated to the establishment of prognostic nomogram, of which the accuracy was measured by the calibration curve and the concordance index (C-index). RESULTS: In total, 8616 patients were identified with 4.6% of 3-year breast cancer- specific death (BCSD) and 8.6% of 5-year BCSD. The most common SPC among BCFPM patients were female BC and lung cancer. Besides, the median latency time between BC and SPC was 22 months. At a ratio of 7:3, all patients were randomly categorized into a training cohort (n = 6032) and a validation cohort (n = 2584). By a proportional subdistribution hazards regression analysis, the following factors were considered to own independent prognostic abilities of BCSS: subtypes, grade, T classification, N classification, radiation, and sites of SPC. The nomogram could accurately predict 3-year and 5-year breast cancer-associated survival of BCFPM patients with high internal and external validated C-index, 0.715 (95% CI, 0.691-0.739), and 0.683 (95% CI, 0.642-0.724), respectively. CONCLUSIONS: BC survivors remained a high risk of developing SPC and considerably shortened survival time. In this study, a favorable nomogram was constructed to as a prediction model for 3-year and 5-year BCSS of BCFPM patients, largely intending to prolong the life of these patients by assisting clinicians to make individualized follow-up plans.

Risk Signature of Cancer-Associated Fibroblast-Secreted Cytokines Associates With Clinical Outcomes of Breast Cancer.

Cancer-associated fibroblasts (CAFs) are key components in tumor microenvironment (TME). The secreted products of CAFs play important roles in regulating tumor cells and further impacting clinical prognosis. This study aims to reveal the relationship between CAF-secreted cytokines and breast cancer (BC) by constructing the risk signature. We performed three algorithms to reveal CAF-related cytokines in the TCGA BC dataset and identified five prognosis-related cytokines. Then we used single-cell RNA sequencing (ScRNA-Seq) datasets of BC to confirm the expression level of these five cytokines in CAFs. METABRIC and other independent datasets were utilized to validate the findings in further analyses. Based on the identified five-cytokine signature derived from CAFs, BC patients with high-risk score (RS) had shorter overall survival than low-RS cases. Further analysis suggested that the high-RS level correlated with cell proliferation and mast cell infiltration in BCs of the Basal-like subtype. The results also indicated that the level of RS could discriminate the high-risk BC cases harboring driver mutations (i.e., PI3KCA, CDH1, and TP53). Additionally, the status of five-cytokine signature was associated with the frequency and molecular timing of whole genome duplication (WGD) events. Intratumor heterogeneity (ITH) analysis among BC samples indicated that the high-RS level was associated with the increase of tumor subclones. This work demonstrated that the prognostic signature based on CAF-secreted cytokines was associated with clinical outcome, tumor progression, and genetic alteration. Our findings may provide insights to develop novel strategies for early intervention and prognostic prediction of BC.

Safety profile of poly (ADP-ribose) polymerase (PARP) inhibitors in cancer: a network meta-analysis of randomized controlled trials.

BACKGROUND: Poly (ADP-ribose) polymerase (PARP) inhibitors, which are among the most important breakthroughs in precision medicine, have played a crucial role in cancer treatment. Understanding the toxicity profiles of the different PARP inhibitors will improve strategic treatment in clinical practice. METHODS: PubMed, Cochrane Library, and Web of Science were systematically searched to include related studies published in English between January 2009 and February 2020. Only prospective, phase II and III randomized controlled trials were included. The following treatment groups were analyzed: niraparib, talazoparib, olaparib, rucaparib, conventional therapy (chemotherapy), one PARP inhibitor with one angiogenesis inhibitor, and placebo. Baseline data and adverse event data were extracted from the Bayesian random-effects network meta-analysis. RESULTS: Fourteen phase II and III randomized controlled trials (4,336 patients) were included. When considering grade 3-5 adverse events, olaparib may be a better choice (probability =57%), followed by conventional therapy (50%), talazoparib (45%), rucaparib (75%), niraparib (77%), and a PARP inhibitor with one angiogenesis inhibitor (94%). Niraparib and rucaparib had higher risks for hematological and gastrointestinal toxicities, respectively. Talazoparib was safer for gastrointestinal function. Constipation and neutropenia were less observed in olaparib, but the risks for anorexia increased. The combination of PARP inhibitor and angiogenesis inhibitor increased the risk of general, metabolic, and gastrointestinal disorders. CONCLUSIONS: This network meta-analysis suggested that the toxicity spectrum of each PARP inhibitor is different. Olaparib had the best safety profile among all PARP inhibitors because of its mild toxicity and narrow spectrum. This study may guide clinicians and support further research.

Comprehensive description of the current breast cancer microenvironment advancements via single-cell analysis.

Breast cancer is a heterogeneous disease with a complex microenvironment consisting of tumor cells, immune cells, fibroblasts and vascular cells. These cancer-associated cells shape the tumor microenvironment (TME) and influence the progression of breast cancer and the therapeutic responses in patients. The exact composition of the intra-tumoral cells is mixed as the highly heterogeneous and dynamic nature of the TME. Recent advances in single-cell technologies such as single-cell DNA sequencing (scDNA-seq), single-cell RNA sequencing (scRNA-seq) and mass cytometry have provided new insights into the phenotypic and functional diversity of tumor-infiltrating cells in breast cancer. In this review, we have outlined the recent progress in single-cell characterization of breast tumor ecosystems, and summarized the phenotypic diversity of intra-tumoral cells and their potential prognostic relevance.