Novel Mitochondria-Based Targeting Restores Responsiveness in Therapeutically Resistant Human Lung Cancer Cells

Overcoming Resistance in Prostate Cancer Therapy Using a DZ-Simvastatin Conjugate

Prostate cancer (PC), particularly its metastatic castration-resistant form (mCRPC), is a leading cause of cancer-related deaths among men in the Western world. Traditional systemic treatments, including hormonal therapy and chemotherapy, offer limited effectiveness due to tumors' inherent resistance to these therapies. Moreover, they often come with significant side effects. We have developed a delivery method using a tumor-cell-specific heptamethine carbocyanine dye (DZ) designed to transport therapeutic agents directly to tumor cells. This research evaluated simvastatin (SIM) as the antitumor payload because of its demonstrated chemopreventive effects on human cancers and its well-documented safety profile. We designed and synthesized a DZ-SIM conjugate for tumor cell targeting. PC cell lines and xenograft tumor models were used to assess tumor-cell targeting specificity and killing activity and to investigate the corresponding mechanisms. DZ-SIM treatment effectively killed PC cells regardless of their androgen receptor status or inherent therapeutic resistance. The conjugate targeted and suppressed xenograft tumor formation without harming normal cells of the host. In cancer cells, DZ-SIM was enriched in subcellular organelles, including mitochondria, where the conjugate formed adducts with multiple proteins and caused the loss of transmembrane potential, promoting cell death. The DZ-SIM specifically targets PC cells and their mitochondria, resulting in a loss of mitochondrial function and cell death. With a unique subcellular targeting strategy, the conjugate holds the potential to outperform existing chemotherapeutic drugs. It presents a novel strategy to circumvent therapeutic resistance, offering a more potent treatment for mCRPC.

Targeting the mitochondria in chronic respiratory diseases

Mitochondria are one of the basic essential components for eukaryotic life survival. It is also the source of respiratory ATP. Recently published studies have demonstrated that mitochondria may have more roles to play aside from energy production. There is an increasing body of evidence which suggest that mitochondrial activities involved in normal and pathological states contribute to significant impact to the lung airway morphology and epithelial function in respiratory diseases such as asthma, COPD, and lung cancer. This review summarizes the pathophysiological pathways involved in asthma, COPD, lung cancer and highlights potential treatment strategies that target the malfunctioning mitochondria in such ailments. Mitochondria are responsive to environmental stimuli such as infection, tobacco smoke, and inflammation, which are essential in the pathogenesis of respiratory diseases. They may affect mitochondrial shape, protein production and ultimately cause dysfunction. The impairment of mitochondrial function has downstream impact on the cytosolic components, calcium control, response towards oxidative stress, regulation of genes and proteins and metabolic activities. Several novel compounds and alternative medicines that target mitochondria in asthma and chronic lung diseases have been discussed here. Moreover, mitochondrial enzymes or proteins that may serve as excellent therapeutic targets in COPD are also covered. The role of mitochondria in respiratory diseases is gaining much attention and mitochondria-based treatment strategies and personalized medicine targeting the mitochondria may materialize in the near future. Nevertheless, more in-depth studies are urgently needed to validate the advantages and efficacy of drugs that affect mitochondria in pathological states.

Novel DZ-SIM Conjugate Targets Cancer Mitochondria and Prolongs Survival in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a disease with no effective therapeutics. We have developed a novel targeted therapy drug consisting of a tumor-targeting ligand, near-infrared (NIR) organic heptamethine carbocyanine dye (HMCD), and HMG-CoA inhibitor simvastatin (SIM), and assessed its efficacy in PDAC. PDAC cell specific targeting of DZ-SIM was measured by determining the fluorescence in cells and animals. Mitochondrial bioenergetics and functions were measured by Seahorse and flow cytometry, respectively. Apoptosis was assessed by DNA fragmentation, AnnexinV/Propidium Iodide staining, and TUNEL. Markers of cell invasion, epithelial-to-mesenchymal transition, and cancer stemness were measured. The effect of DZ-SIM on survival, tumor growth and metastasis was measured in the Krasþ/LSLG12D;Trp53þ/LSLR172H;Pdx-1-Cre (KPC) transgenic mice and in syngeneic and subcutaneous PDAC models. NIR fluorescence imaging showed specific localization of DZ-SIM to cancer, but not to normal cells and tissues. DZ-SIM significantly inhibited tumor growth and re-sensitized therapeutically resistant PDAC cells to conventional therapies. DZ-SIM killed cancer cells through unique pathways involving decreasing mitochondrial bioenergetics, including oxygen consumption and ATP production, and increasing ROS production. Mitochondrial depletion prevented the effect of DZ-SIM. Administration of DZ-SIM in 3 PDAC animal models resulted in a marked increase in survival and a decrease in tumor growth and metastasis.

Emerging strategies to overcome resistance to third-generation EGFR inhibitors

Epidermal growth factor receptor (EGFR), the receptor for members of the epidermal growth factor family, regulates cell proliferation and signal transduction; moreover, EGFR is related to the inhibition of tumor cell proliferation, angiogenesis, invasion, metastasis, and apoptosis. Therefore, EGFR has become an important target for the treatment of cancer, including non-small cell lung cancer, head and neck cancer, breast cancer, glioma, cervical cancer, and bladder cancer. First- to third-generation EGFR inhibitors have shown considerable efficacy and have significantly improved disease prognosis. However, most patients develop drug resistance after treatment. The challenge of overcoming intrinsic and acquired resistance in primary and recurrent cancer mediated by EGFR mutations is thus driving the search for alternative strategies in the design of new therapeutic agents. In view of resistance to third-generation inhibitors, understanding the intricate mechanisms of resistance will offer insight for the development of more advanced targeted therapies. In this review, we discuss the molecular mechanisms of resistance to third-generation EGFR inhibitors and review recent strategies for overcoming resistance, new challenges, and future development directions.

EGFR signaling pathway as therapeutic target in human cancers

Epidermal Growth Factor Receptor (EGFR) enacts major roles in the maintenance of epithelial tissues. However, when EGFR signaling is altered, it becomes the grand orchestrator of epithelial transformation, and hence one of the most world-wide studied tyrosine kinase receptors involved in neoplasia, in several tissues. In the last decades, EGFR-targeted therapies shaped the new era of precision-oncology. Despite major advances, the dream of converting solid tumors into a chronic disease is still unfulfilled, and long-term remission eludes us. Studies investigating the function of this protein in solid malignancies have revealed numerous ways how tumor cells dysregulate EGFR function. Starting from preclinical models (cell lines, organoids, murine models) and validating in clinical specimens, EGFR-related oncogenic pathways, mechanisms of resistance, and novel avenues to inhibit tumor growth and metastatic spread enriching the therapeutic portfolios, were identified. Focusing on non-small cell lung cancer (NSCLC), where EGFR mutations are major players in the adenocarcinoma subtype, we will go over the most relevant discoveries that led us to understand EGFR and beyond, and highlight how they revolutionized cancer treatment by expanding the therapeutic arsenal at our disposal.