Search Results (194)

Cancer is no longer considered as an isolated event. Rather, it occurs because of a complex biological drive orchestrating different cell types, growth factors, cytokines, and signaling pathways within the tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) are the most populous stromal cells within the complex ecosystem of TME, with significant heterogeneity and plasticity in origin and functional phenotypes. Very enigmatic cells, CAFs determine the progress and outcomes of tumors through extensive reciprocal signaling with different tumors infiltrating immune cells in the TME. In their biological drive, CAFs release numerous chemical mediators and utilize various signaling pathways to recruit and modulate tumor-infiltrating immune cells. The CAF-induced secretome and exosomes render immune cells ineffective for their antitumor activities. Moreover, by upregulating immune inhibitory checkpoints, CAFs create an immunosuppressive TME that impedes the susceptibility of tumor cells to tumor-infiltrating lymphocytes (TILs). Further, by depositing and remodeling extracellular matrix (ECM), CAFs reshape the TME, which enhances tumor growth, invasion, metastasis, and chemoresistance. Understanding of CAF biology and its crosstalk with tumor-infiltrating immune cells is crucial not only to gain insight in tumorigenesis but to optimize the potential of novel targeted immunotherapies for cancers. The complex relationships between CAFs and tumor-infiltrating immune cells remain unclear and need further study. Herein, in this narrative review we have focused on updates of CAF biology and its interactions with tumor-infiltrating immune cells in generating immunosuppressive TME and resistance to cell death. Full article

Background/Objectives: Mesenchymal stem cells (MSCs) possess immunomodulatory properties, tumor-homing, and low immunogenicity, making them attractive for cell-based cancer therapies, but their role in colorectal cancer (CRC) remains controversial. The MSC1 phenotype, a pro-inflammatory, tumor-suppressive state induced by short-term, low-dose LPS activation via TLR4, has shown therapeutic promise but remains poorly characterized in CRC. We aimed to elucidate MSC1’s tumor-suppressive mechanisms and validate its activity against CRC cells using an integrated bioinformatics and in vitro approach. Methods: We constructed a high-confidence protein-protein interaction (PPI) network in Wharton’s jelly-derived MSCs (WJ-MSCs) following TLR4 activation to uncover enriched signaling pathways, transcriptional regulators, and secreted factors. Functional and transcriptional enrichment analyses pinpointed key mechanisms. We then co-cultured MSC1 cells with CRC cells to assess effects on proliferation and metabolism. Results: Network analysis revealed six tumor-suppressive mechanisms of MSC1 cells: (i) Metabolic reprogramming via enhanced glucose and lipid uptake, phosphoinositide signaling, and membrane/protein recycling, (ii) Robust antioxidant defenses, including SOS signaling and system xc⁻, (iii) Extracellular matrix stabilization and laminin-111–integrin-mediated adhesion, (iv) Secretome with direct anti-cancer effects, (v) Regulation of survival and cancer-associated fibroblasts (CAFs) formation inhibition through balanced proliferation, apoptosis, and epigenetic signals, (vi) Controlled pro-inflammatory signaling with anti-inflammatory feedback. In vitro, MSC1 cells significantly suppressed CRC cell proliferation and metabolic activity versus controls. Conclusions: This study provides the first mechanistic map of MSC1’s tumor-suppressive functions in CRC, extending beyond immunomodulation to include metabolic competition, ECM stabilization, and anti-cancer secretome activity. These findings establish MSC1 cells as a novel therapeutic strategy for CRC in cell-based cancer therapies. Full article

Systemic cancer progression culminating in metastatic disease is implicitly dependent on tumour cell interactions with the vascular system. Indeed, different facets of the micro- and macro-vasculature can be regarded as rate-limiting ‘vascular checkpoints’ in the process of cancer dissemination. The underlying complex communication networks drive tumour neovascularization, angiogenesis, immunoregulation, activation of the coagulation system, angiocrine interactions, and non-angiogenic vascular responses across multiple cancer types. Yet, each cancer may represent a unique vascular interaction scenario raising a prospect of targeted modulation of blood and lymphatic vessels for therapeutic purposes, beyond the traditional notion of tumour anti-angiogenesis. While the emphasis of studies aiming to understand this circuitry has traditionally been on soluble, or ‘mono-molecular’ mediators, the rise of the particulate secretome encompassing heterogeneous subpopulations of extracellular vesicles (EVs; including exosomes) and particles (EPs) brings another dimension into the tumour–vascular communication web during the process of metastasis. EVs and EPs are nanosized cellular fragments, the unique nature of which lies in their ability to encapsulate, protect and deliver to target cells a range of bioactive molecular entities (proteins, RNA, DNA) assembled in ways that enable them to exert a wide spectrum of biological activities. EVs and EPs penetrate through biological barriers and are capable of intracellular uptake. Their emerging vascular functions in metastatic or infiltrative cancers are exemplified by their roles in pre-metastatic niche formation, thrombosis, vasectasia or angiocrine regulation of cancer stem cells. Here, we survey some of the related evidence supporting the biological, diagnostic and interventional significance of EVs/EPs (EVPs) in disseminated neoplastic disease. Full article

Background/Objectives: Nucleic acid-based anticancer vaccines are becoming a very active field in the fight against cancer. Here, our goal was to generate an oral DNA vaccine targeting the angiogenic peptide, proadrenomedullin N-terminal 20 peptide (PAMP). Methods: An expression plasmid (PcPAMP) was generated by fusing the tetanus toxin epitopes P2 and P30 to the mouse PAMP sequence to counteract self-tolerance, and the empty plasmid was used as a negative control (PcNeg). The plasmids were introduced into Salmonella typhimurium bacteria that were then transformed into bacterial ghosts. C57BL/6J mice were orally immunized with the ghosts five times at 2-week intervals. Then, B16-F10 melanoma cells were injected into the tail vein to generate lung metastases. Furthermore, naïve CD4⁺ T cells were exposed to PAMP, and their secretome was analyzed by proximity extension assays. Results: Significant levels of anti-PAMP immunoglobulins were detected in the blood of PcPAMP-vaccinated mice and their levels of spleen CD8⁺ T cells were significantly higher than in those treated with PcNeg, indicating that self-tolerance was effectively broken. Although the number and size of lung metastases was similar between both experimental groups, there was a significant reduction in intratumoral angiogenesis and in cancer cell proliferation index in the PcPAMP group. Furthermore, these animals showed an intense infiltration of lymphocytes, including regulatory T cells, and M2-like macrophages into the metastases, that was not evident in the PcNeg group. In addition, PAMP induced upregulation of IL1β, IL6, IL7, IL12, IL27, TNFα, and FGF21, and downregulation of IL16 in naïve CD4⁺ T cells. Conclusions: Although the vaccine was not effective in reducing tumor growth, new proliferative and immune functions have been described for PAMP. These new functions include induction of melanoma proliferation and modulation of lymphocyte and macrophage tumor infiltration dynamics. Full article

Breast cancer (BC) is globally becoming a great challenge, being both the most diagnosed cancer and the leading cause of death in women. In addition to cancer cells, many bacteria co-inhabit BC, which differ in type and number from the resident microbiota found in healthy breast tissue. While many reports have demonstrated the ability of different bacteria to dysregulate BC’s metabolites, the reciprocal effect of these metabolites on the bacterial microbiota has not yet been investigated. Herein, we assess the effect of conditioned media (CM) from a triple-negative BC cell line (MDA-MB-231) on the metabolic profile of Pseudomonas aeruginosa (P. aeruginosa), an important breast resident Gram-negative bacteria that influence oncogenesis. Optical density and scanning electron microscopes were used to assess the impact of MDA-MB-231-CM (BC-CM) on P. aeruginosa growth and morphological changes, respectively. In addition, liquid chromatography–high-resolution mass spectrometry was used to identify metabolic changes in P. aeruginosa and their secretomes in response to the BC-CM. The BC-CM significantly suppressed the growth of P. aeruginosa in the log phase and induced concentration-dependent cytopathological changes in their cell walls. The metabolites of P. aeruginosa were dysregulated considerably depending on the time of exposure to the BC-CM. When treated with the BC-CM, P. aeruginosa induced the purine alkaloid spliceostatin (FR901464), a prominent antitumor metabolite. The BC-CM also promoted other P. aeruginosa metabolites such as amino acids, phosphoribosyl-AMP, 2-aminoacetophenone, pyochelin I, guanosine monophosphate, riboflavin, and terpenoids, which are capable of interfering with oncogenesis. Nine of the significantly identified metabolites from the 0–3 h comparison and four of those identified from the 0–6 h comparison have potential roles in influencing cancer cell behavior. Our findings demonstrate the ability of triple-negative BC-CM not only to alter the growth and morphology of P. aeruginosa but also to modulate their metabolic profile. A better understanding of the influence of BC on certain resident breast microbiomes, such as P. aeruginosa, may open a new therapeutic intervention opportunity for the treatment of cancer. Full article

Background/Objectives: Dendritic-cell-derived exosomes (DEXs) have demonstrated immunostimulatory potential in cancer immunotherapy, yet their clinical application remains constrained by their cryodependence, compositional heterogeneity, and limited scalability. To address these limitations, we developed an ultrapurified phospholipoproteic complex (PLPC), a dendritic-secretome-derived formulation stabilized through ultracentrifugation and lyophilization that has been engineered to preserve its immunological function and structural integrity. Methods: Secretomes were processed under four conditions (fresh, concentrated, cryopreserved, and lyophilized PLPC) and compared through proteomic and functional profiling. Mass spectrometry (LC-MS/MS) analysis revealed that the PLPC retained a significantly enriched set of immunoregulatory proteins—including QSOX1, CCL22, and SDCBP—and exhibited superior preservation of post-translational modifications. Results: Ex vivo co-culture assays with human peripheral blood mononuclear cells (PBMCs) demonstrated that the PLPC induced robust secretion of IFN-γ, TNF-α, and IL-6 while concurrently suppressing IL-10, achieving an IFN-γ/IL-10 ratio exceeding 3.5. Flow cytometry confirmed the substantial activation of both CD4⁺ and CD8⁺ T cells, while apoptosis assays showed selective tumor cytotoxicity (>55% tumor apoptosis) with minimal impact on non-malignant cells (>92% viability). Conclusions: These findings establish the PLPC as a reproducible, Th1-polarizing immunomodulator with selective antitumor activity, ambient-temperature stability, and compatibility with non-invasive administration. Overall, the PLPC emerges as a scalable, cell-free immunotherapeutic platform with translational potential to reprogram immune suppression in metastatic therapy-resistant cancer settings. Full article

Tumor-derived extracellular vesicles (EVs) play an important role in cancer progression. Neutral sphingomyelinases (nSMases) are lipid-modifying enzymes that modulate the secretion of EVs from cells. How nSMase activity and therefore ceramide generation affect the composition and functionality of secreted EVs is not fully understood. Here, we aimed to investigate the expression of nSMases 1 and 2 in prostate cancer (PCa) tissue and their role in EV composition and secretion for prostate cancer cell migration. Reduced nSMase 1 and 2 expression was found in prostate cancer and correlated with the age of the patient. When nSMase 2 was inhibited by GW4869 in PCa cells (PC3 and DU145), the EV secretome was significantly altered, while the number of EVs and the total protein content of released EVs were not significantly changed. Using proteomic analysis, we found that extracellular matrix proteins, such as SDC4 (Syndecan-4) and SRPX-2, were differentially secreted on EVs from GW4869-treated PC3 cells. In scratch wound migration assays, GW4869 significantly increased migration compared to control PC3 cells but not DU145 cells, while SDC4 knockdown significantly reduced the migration of PC3 cells. These and other nSMase-2-dependent secreted proteins are interesting candidates for understanding the role of stress-induced EVs in the progression of prostate cancer. Full article

Background: Radiotherapy is a key treatment for cancer, effectively controlling local tumor growth through DNA damage that induces senescence or apoptosis in cancer cells. However, radiotherapy can trigger complex cellular reactions, such as cell senescence, which is characterized by irreversible cell cycle arrest and the secretion of pro-inflammatory factors known as the senescent-associated secretory phenotype (SASP). Methods: This study investigates the regulatory role of ALDH1A3, a key enzyme implicated in cancer cell metabolism and radiotherapy resistance, in the induction of senescence and SASP. Using in vitro models, we demonstrate that ALDH1A3 knockdown accelerates cellular senescent-like phenotype while regulating the SASP through the cGAS–STING immune response pathway. Results: Our results indicate that while ALDH1A3 knockdown promotes senescence, it reduces the secretion of pro-inflammatory factors via inhibition of the cGAS–STING pathway, potentially mitigating SASP-related tumor progression. Conclusions: These findings provide insights into the molecular mechanisms underlying prostate cancer cell senescence and suggest that ALDH1A3 could be a potential therapeutic target to enhance the efficacy of radiotherapy while controlling the adverse effects of SASP. Full article

Ovarian cancer (OC) is characterized by high mortality rates due to late diagnosis, recurrence, and metastasis. Here, we show that extracellular signaling molecules secreted by adipose-derived mesenchymal stem cells (ASCs) and OC cells—either in the conditioned medium (CM) or within small extracellular vesicles (sEVs)—modulate cellular responses and drive OC progression. ASC-derived sEVs and CM secretome promoted OC cell colony formation, invasion, and migration while upregulating tumor-associated signaling pathways, including TGFβ/Smad, p38MAPK/ERK1/2, Wnt/β-catenin, and MMP-9. Additionally, OC-derived sEVs and CM induced a pro-tumorigenic phenotype in ASCs, enhancing their invasiveness and expression of tumor-associated factors. Notably, both ASCs and OC cells exhibited increased expression of E-cadherin and Snail/Slug proteins, key markers of epithelial/mesenchymal hybrid phenotype, enhancing cellular plasticity and metastatic potential. We also demonstrated that these cellular features are, at least in part, due to the presence of tumor-supportive molecules such as TNF-α, Tenascin-C, MMP-2, and SDF-1α in the CM secretome of ASCs and OC cells. In silico analyses linked these molecular changes to poor prognostic outcomes in OC patients. These findings highlight the critical role of sEVs and tumor/stem cell-derived secretome in OC progression through bidirectional interactions that impact cellular behavior and phenotypic transitions. We suggest that targeting EV-mediated communication could improve therapeutic strategies and patient outcomes. Full article

Background: Metastatic prostate cancer (mPCa) is marked by heterogeneity and therapy resistance, which arise from prolonged therapy regimens. This heterogeneity is reflected in various morphologic and genetic characteristics, biomarker expression, and other molecular mechanisms, thereby contributing to the complexity of the disease. Methods: To investigate tumor heterogeneity, the effects of androgen targeting therapy (ADT) on single-cell PSA secretion was assessed by analyzing the prostate cancer cell lines using a modified ELISpot platform. The FACS and cytospin techniques were employed to understand the influence of the cell cycle on PSA secretion patterns. Additionally, a proteome array was used to identify potential biomarkers from different PCa cell lines with varying metastatic potential. Results: Among the various PCa cell lines examined, PSA expression and secretion could be visualized only from the LNCaPs. PSA secretion from circulating tumor cells (CTCs) further confirmed the validity of this assay. These LNCaPs exhibited heterogeneity in single-cell intracellular and extracellular PSA expression and in their ADT responses. LNCaPs in the G1 phase showed higher PSA secretion than in the S or G2/M phase. Apart from PSA, Cathepsin D, Progranulin, IL-8, Serpin E1, and Enolase 2 were identified as secretome markers from the metastatic PCa cell lines. Conclusions: We observed variability in PSA secretion in LNCaP in response to anti-androgen treatment and a cell cycle-dependent secretion pattern. The notable presence of Progranulin and Cathepsin D in metastatic cell lines makes them promising candidates for use in multiplexing and single-cell platforms, potentially advancing our understanding and treatment of this disease. Full article

Background: Tumor-associated macrophages (TAMs) are key players in the colorectal cancer (CRC) tumor microenvironment (TME), representing the most abundant immune cells within it. The interplay between the intestinal microbiota, macrophages, and cancer cells significantly impacts tumor progression by driving macrophage polarization. Particularly, the polarization into the pro-tumoral M2-like TAM phenotype promotes the extracellular matrix remodeling, cancer cell proliferation, metastasis, immune suppression, and therapy resistance. Probiotic metabolites can disrupt this crosstalk, possibly reverting the TAM polarization toward a pro-inflammatory anti-tumoral phenotype, thus potentially benefiting the intestinal mucosa and opposing CRC progression. Previously, we showed that Lactiplantibacillus plantarum OC01 metabolites counter interleukin (IL)-6-induced CRC proliferation and migration. Methods: Here, we explore how probiotics affect CRC secretome and how this influences TAM polarization, which then impacts CRC malignancy. Results: The conditioning medium (CM) from CRC cells indeed promoted the polarization of macrophage toward the M2-like phenotype, whereas the CM from CRC pre-treated with L. plantarum OC01 metabolites induced a pro-inflammatory macrophage phenotype, characterized by NLRP3 inflammasome activation and reactive oxygen species (ROS) production, and by decreased expression of the M2 phenotype markers CD206 and CD163. Consistently, the expression of tumor growth factor (TGF)-β, a promoter of M2 macrophage polarization, was reduced in CRC cells treated with L. plantarum OC01. The pro-inflammatory macrophages inhibited CRC proliferation and migration. Conclusions: Overall, our study highlights the potential of metabolites from L. plantarum OC01 to reprogram the metabolism in cancer cells and thus reshape the TME by shifting TAMs toward a more inflammatory and anti-tumoral phenotype, emphasizing the promise of probiotics in advancing novel therapeutic approaches for CRC. Full article

Colorectal cancer (CRC) and lung cancer (LC) are leading causes of cancer-related mortality, highlighting the need for minimally invasive diagnostic, prognostic, and predictive markers for these cancers. Proteins secreted by a tumor into the extracellular space directly, known as the tumor secretome, as well as proteins in the extra-cellular vesicles (EVs), represent an attractive source of biomarkers for CRC and LC. We performed proteomic analyses on secretome and EV samples from LC (A549, NCI-H23, NCI-H460) and CRC (Caco2, HCT116, HT-29) cell lines and targeted mass spectrometry on EVs from plasma samples of 20 patients with CRC and 19 healthy controls. A total of 782 proteins were identified across the CRC and LC secretome and EV samples. Of these, 22 and 44 protein markers were significantly elevated in the CRC and LC samples, respectively. Functional annotation revealed enrichment in proteins linked to metastasis and tumor progression for both cancer types. In EVs isolated from the plasma of patients with CRC, ITGB3, HSPA8, TUBA4A, and TLN1 were reduced, whereas FN1, SERPINA1, and CST3 were elevated, compared to healthy controls. These findings support the development of minimally invasive liquid biopsy methods for the detection, prognosis, and treatment monitoring of LC and CRC. Full article

Mesenchymal stem cell (MSC) treatments take advantage of the ability of these cells to migrate to target sites, although they have been shown to move in response to tumor influence. Currently, tools are being developed to detect these opportune changes in cellular behavior patterns. No reports of such changes in the morphological patterns or migration of MSCs in the presence of a tumor environment, which would provide information of high diagnostic value, have been made. We determined the changes in the cytoskeleton and migration of MSCs exposed to the secretome of breast tumor cells via bioimpedance records. MSCs were cultured and incubated in the presence of 24 and 48 h secretomes of the MCF-7 tumor cell line. The proliferation, migration, morphology, cytoskeleton, and electrical bioimpedance were evaluated at 48 h for cells treated with 24 and 48 h secretomes. Secretomes induced early morphological changes related to the migration of MSCs, directly confirmed via bioimpedance, but no changes in cell proliferation were found. These changes cannot be related to a transformation or malignancy phenotype. The modification of the bioimpedance patterns recorded from the first hours suggests that this method can be applied in an innovative way to detect early changes in a cellular population in the clinical diagnostic setting. Full article

Glioblastoma (GB) is one of the most aggressive and treatment-resistant cancers due to its complex tumor microenvironment (TME). We previously showed that GB progression is dependent on the aberrant induction of chaperone-mediated autophagy (CMA) in pericytes (PCs), which promotes TME immunosuppression through the PC secretome. The secretion of extracellular matrix (ECM) proteins with anti-tumor (Lumican) and pro-tumoral (Osteopontin, OPN) properties was shown to be dependent on the regulation of GB-induced CMA in PCs. As biomarkers are rarely studied in TME, in this work, we aimed to validate Lumican and OPN as prognostic markers in the perivascular areas of the peritumoral niche of a cohort of GB patients. Previously, we had validated their expression in GB xenografted mice presenting GB infiltration (OPN) or GB elimination (Lumican) dependent on competent or deficient CMA PCs, respectively. Then, patient sample classification by GB infiltration into the peritumoral brain parenchyma was related to GB-induced CMA in microvasculature PCs, analyzing the expression of the lysosomal receptor, LAMP-2A. Our results revealed a correlation between GB-induced CMA activity in peritumoral PCs and GB patients’ outcomes, identifying three degrees of severity. The perivascular expression of both immune activation markers, Iba1 and CD68, was related to CMA-dependent PC immune function and determined as useful for efficient GB prognosis. Lumican expression was identified in perivascular areas of patients with less severe outcome and partially co-localizing with PCs presenting low CMA activity, while OPN was primarily found in perivascular areas of patients with poor outcome and partially co-localizing with PCs presenting high CMA activity. Importantly, we found sex differences in the incidence of middle-aged patients, being significantly higher in men but with worse prognosis in women. Our results confirmed that Lumican and OPN in perivascular areas of the GB peritumoral niche are effective predictive biomarkers for evaluating prognosis and monitoring possible therapeutic immune responses dependent on PCs in tumor progression. Full article

The tumor secretome comprises the totality of protein factors secreted by various cell components within the tumor microenvironment, serving as the primary medium for signal transduction between tumor cells and between tumor cells and stromal cells. The deletion or mutation of the p53 gene leads to alterations in cellular secretion characteristics, contributing to the construction of the tumor microenvironment in a cell non-autonomous manner. This review discusses the critical roles of mutant p53 in regulating the tumor secretome to remodel the tumor microenvironment, drive tumor progression, and influence the plasticity of cancer-associated fibroblasts (CAFs) as well as the dynamics of tumor immunity by focusing on both secreted protein expression and secretion pathways. The aim is to provide new insights for targeted cancer therapies. Full article