Biomarkers are biomolecules used to identify or predict the presence of a specific disease or condition. They play an important role in early diagnosis and may be crucial for treatment. MicroRNAs (miRNAs), a group of small non-coding RNAs, are more and more regarded as promising biomarkers for several reasons. Dysregulation of miRNAs has been linked with development of several diseases, including many different types of cancer, and abnormal levels can be present in early stages of tumor development. Because miRNAs are stable molecules secreted and freely circulating in blood and urine, they can be sampled with little or no invasion. Here, we present an overview of the current literature, focusing on the types of cancers for which dysregulation of miR-665 has been associated with disease progression, recurrence, and/or prognosis. It needs to be emphasized that the role of miR-665 sometimes seems ambiguous, in the sense that it can be upregulated in one cancer type and downregulated in another and can even change during the progression of the same cancer. Caution is thus needed before using miR-665 as a biomarker, and extrapolation between different cancer types is not advisable. Moreover, more detailed understanding of the different roles of miR-665 will help in determining its potential as a diagnostic and prognostic biomarker.

Multidrug-resistant bacteria present a significant public health challenge; such pathogens exhibit reduced susceptibility to conventional antibiotics, limiting current treatment options. Cationic non-ribosomal peptides (CNRPs) such as brevicidine and polymyxins have emerged as promising candidates to block Gram-negative bacteria. To investigate the capability of bacteria to biosynthesize CNRPs, and specifically polymyxins, over 11,000 bacterial genomes were mined in silico. Paenibacillus polymyxa was identified as having a robust biosynthetic capacity, based on multiple polymyxin gene clusters. P. polymyxa biosynthetic competence was confirmed by metabolite characterization via HPLC purification and MALDI TOF/TOF analysis. When grown in a selected medium, the metabolite yield was 4 mg/L with a 20-fold specific activity increase. Polymyxin B (PMB) was assayed with select nosocomial pathogens, including Pseudomonas aeruginosa, Klebsiella pneumonia, and Acinetobacter baumaii, which exhibited minimum inhibitory concentrations of 4, 1, and 1 µg/mL, respectively.

Receptor dysregulation is a hallmark of cancer and a major driver of tumor initiation, progression, and therapeutic resistance. Among the most clinically relevant receptors are the epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), estrogen receptor (ER), and androgen receptor (AR), which regulate critical processes including cell proliferation, survival, and metastasis. Genetic alterations, receptor overexpression, and aberrant signaling can lead to persistent activation of these pathways, promoting oncogenic progression. Advances in the understanding of EGFR, HER2, ER, and AR signaling have enabled the development of targeted therapies that have significantly improved clinical outcomes. However, therapeutic resistance, signaling crosstalk, and tumor heterogeneity continue to limit treatment efficacy. This review summarizes the mechanisms underlying the dysregulation of these receptor pathways, their roles in cancer development, and current and emerging therapeutic strategies targeting receptor-driven malignancies. A better understanding of these signaling networks may facilitate the development of more effective biomarkers and precision oncology approaches.