Breast and lung cancers are among the top cancer types in terms of incidence and mortality burden worldwide. One of the challenges in the treatment of breast and lung cancers is their resistance to administered drugs, as observed with angiogenesis inhibitors. Based on clinical and pre-clinical findings, these two types of cancers have gained the ability to resist angiogenesis inhibitors through several mechanisms that rely on cellular and extracellular factors. This resistance is mediated through angiogenesis-independent vascularization, and it is related to cancer cells and their microenvironment. The mechanisms that cancer cells utilize include metabolic symbiosis and invasion, and they also take advantage of neighboring cells like macrophages, endothelial cells, myeloid and adipose cells. Overcoming resistance is of great interest, and researchers are investigating possible strategies to enhance sensitivity towards angiogenesis inhibitors. These strategies involved targeting multiple players in angiogenesis, epigenetics, hypoxia, cellular metabolism and the immune system. This review aims to discuss the mechanisms of resistance to angiogenesis inhibitors and to highlight recently developed approaches to overcome this resistance.

The etiology and pathogenesis of odontogenic lesions are poorly understood. Keratin 15 (K15) is a type I cytoskeletal protein that provides structural support to the cells and has been considered to be a stem cell marker. The aim of the present study was to evaluate the expression of K15 in the epithelial lining of dentigerous cysts (DCs), odontogenic keratocysts (OKCs) and ameloblastomas (ABs). The study included 41 samples of DCs (n=13), OKCs (n=12), and AB tissues (n=16). K15 protein expression was evaluated via immunohistochemistry and data were statistically analyzed using a Kruskal‑Wallis test. K15 was expressed in the majority of the studied lesions with various distributions in the different study samples. The Kruskal‑Wallis test revealed non‑significant differences in the expression of K15 among the three odontogenic lesions (P=0.380). The present study confirmed the high expression of K15 in the different epithelial layers of DC, OKC and AB. This type of expression excludes the reliability of regarding K15 as a stem cell marker in DC, OKC and AB. However, K15 may reflect the abnormal differentiation of pathological epithelial cells in these lesions.

Colorectal cancer (CRC) is a major global health burden and a leading cause of cancer-related mortality, with metastasis representing the primary cause of death. Angiogenesis plays a critical role in this process, and macrophages within the tumor microenvironment (TME) are its key regulators. Among these, Tie2-expressing macrophages (TEMs) constitute a distinct pro-angiogenic subset that localizes to perivascular regions and responds to angiopoietin2 (Ang2) signaling. Moreover, TEMs contribute to vessel destabilization and the formation of permissive niches for cancer cell intravasation, linking them to both angiogenic and non-angiogenic modes of malignant tumor progression. The significance of TEMs in CRC remains controversial. This controversy, as we noticed, stems from a confluence of methodological challenges, lack of standardized markers, small-scale studies, inconsistent findings across studies, and the inherent complexity of both CRC biology and macrophage biology. Evidence from preclinical models and patient samples highlights the correlation between Ang2/Tie2 activity, TEM infiltration, and poor prognosis in CRC. This review summarizes current knowledge on the role of TEMs and the Ang/Tie2 axis in CRC angiogenesis, metastasis, and resistance to anti-angiogenic therapies. Advancing our understanding of TEMs may enable novel macrophage-focused strategies to inhibit CRC progression and improve patient outcomes.

Colorectal cancer (CRC) progression occurs through three stages: adenoma (pre-cancerous lesion), carcinoma in situ (CIS) and adenocarcinoma, with tumor stage playing a pivotal role in the prognosis and treatment outcomes. Despite therapeutic advancements, the lack of stage-specific biomarkers hinders the development of accurate diagnostic tools and effective therapeutic strategies. This study aims to identify stage-specific gene expression profiles and key molecular mechanisms in CRC providing insights into molecular alterations across disease progression. Our methodological approach integrates the use of absolute gene set enrichment analysis (absGSEA) on formalin-fixed paraffin-embedded (FFPE)-derived transcriptomic data, combined with large-scale clinical validation and experimental confirmation. A comparative whole transcriptomic analysis (RNA-seq) was performed on FFPE samples including adenoma (n = 10), carcinoma in situ (CIS) (n = 8) and adenocarcinoma (n = 11) samples. Using absGSEA, we identified significant cellular pathways and putative molecular biomarkers associated with each stage of CRC progression. Key findings were then validated in a large independent CRC patient cohort (n = 1926), with survival analysis conducted from 1336 patients to assess the prognostic relevance of the candidate biomarkers. The key differentially expressed genes were experimentally validated using real-time PCR (RT-qPCR). Pathway analysis revealed that in CIS, apoptotic processes and Wnt signaling pathways were more prominent than in adenoma samples, while in adenocarcinoma, transcriptional co-regulatory mechanisms and protein kinase activity, which are critical for tumor growth and metastasis, were significantly enriched compared to adenoma. Additionally, extracellular matrix organization pathways were significantly enriched in adenocarcinoma compared to CIS. Distinct gene signatures were identified across CRC stages that differentiate between adenoma, CIS and adenocarcinoma. In adenoma, ARRB1, CTBP1 and CTBP2 were overexpressed, suggesting their involvement in early tumorigenesis, whereas in CIS, RPS3A and COL4A5 were overexpressed, suggesting their involvement in the transition from benign to malignant stage. In adenocarcinoma, COL1A2, CEBPZ, MED10 and PAWR were overexpressed, suggesting their involvement in advanced disease progression. Functional analysis confirmed that ARRB1 and CTBP1/2 were associated with early tumor development, while COL1A2 and CEBPZ were involved in extracellular matrix remodeling and transcriptional regulation, respectively. Experimental validation with RT-qPCR confirmed the differential expression of the candidate biomarkers (ARRB1, RPS3A, COL4A5, COL1A2 and MED10) across the three CRC stages reinforcing their potential as stage-specific biomarkers in CRC progression. These findings provide a foundation to distinguish between the CRC stages and for the development of accurate stage-specific diagnostic and prognostic biomarkers, which helps in the development of more effective therapeutic strategies for CRC.

• Bacterial genomes reflect the metabolic environment of periapical lesions. • Secondary metabolites and pathogenic proteins drive periapical lesion pathogenesis. • Human transcriptome reflects the acute phase response in periapical abscesses. • Unique secondary metabolites in radicular cysts enhance osmosis. • Regulation of immune effector process is the main player in periapical granulomas.