Tamoxifen–2-hydroxylpropyl-β-cyclodextrin-aggregated nanoassembly for nonbreast estrogen-receptor-positive cancer therapy

Cyclodextrins: Enhancing Drug Delivery, Solubility and Bioavailability for Modern Therapeutics

Cyclodextrins (CDs) have revolutionized the pharmaceutical industry with their ability to enhance the stability, solubility, and bioavailability of a wide range of active substances. These cyclic oligosaccharides, with a unique hydrophilic exterior and hydrophobic cavity, form inclusion complexes with poorly soluble drugs, improving their pharmacokinetic profiles and therapeutic efficacy. This review explores the multifaceted roles of cyclodextrins in pharmaceutical formulations, ranging from oral, ophthalmic, parenteral, and topical applications to their emerging use in targeted therapies, gene delivery, and treatment of neurodegenerative, cardiovascular, and infectious diseases. Cyclodextrins not only improve drug solubility and controlled release but also reduce toxicity and side effects, leading to safer and more effective treatments. Recent advancements, such as cyclodextrin-based nanoparticles, offer promising pathways for cancer therapy, chronic disease management, and personalized medicine. As research continues, cyclodextrins remain at the forefront of innovation in drug delivery systems, ensuring better patient outcomes and expanding the possibilities of modern therapeutics.

Nuclear receptors in ovarian cancer: changing paradigms in cancer therapeutics

Ovarian cancer (OVC) is one of the most common causes of cancer-related deaths in women worldwide. Despite advancements in detection and therapy, the prognosis of OVC remains poor due to late diagnosis and the lack of effective therapeutic options at advanced stages. Therefore, a better understanding of the biology underlying OVC is essential for the development of effective strategies for early detection and targeted therapies. Nuclear receptors (NRs) are a superfamily of 48 transcription factors that, upon binding to their specific ligand, play a vital role in regulating various cellular processes such as growth, development, metabolism, and homeostasis. Accumulating evidence from several studies has shown that their aberrant expression is associated with multiple human diseases. Numerous NRs have shown significant effects in the development of various cancers, including OVC. This review summarizes the recent findings on the role of NRs in OVC, as well as their potential as prognostic and therapeutic markers. Further, the basic structure and signaling mechanism of NRs have also been discussed briefly. Moreover, this review highlights their cellular and molecular mechanisms in chemoresistance and chemosensitization. Further, the clinical trials targeting NRs for the treatment of OVC have also been discussed.

Re-188-tricarbonyl tamoxifen as a theranostic radiopharmaceutical for estrogen receptor expressing breast cancers: radiolabeling, characterization and in-vitro cytotoxic assessment

PURPOSE

Development of a novel theranostic radiopharmaceutical for estrogen receptor, expressing unresectable primary and metastatic breast cancers.

METHODS

Tamoxifen was radiolabeled with Rhenium-188 (Re-188) through tricarbonyl core. Radiolabeled complex was characterized by 1proton nuclear magnetic resonance spectroscopy and Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF). Various quality control tests such as sterility, apyrogenicity, and radiochemical purity (RCP) were performed to assess the suitability of the radiopharmaceutical for intravenous administration. In-vitro cell culture studies were performed for cytotoxic assessment. In addition to this, exposure due to different doses of Re-188-tricarbonyl tamoxifen was also calculated.

RESULTS

Re-188-tricarbonyl and Re-188-tricarbonyl tamoxifen showed more than 99% RCP. Sample was found to be sterile and pyrogens levels were within the permissible limit. Re-188-tricarbonyl tamoxifen was successfully characterized by MALDI-TOF and 1H-NMR spectroscopy. Re-188 (1.480 MBq) and tamoxifen (0.027 or 0.054 µM) individually showed 36 and 70% cell death, respectively. However, radiolabeled complex (Re-188-tricarbonyl tamoxifen) with the same amount of radioactivity (1.480 MBq) increased the cell death to more than 90% with one-fifth to one-tenth molar concentration of tamoxifen (0.0054 μM).

CONCLUSION

Re-188-tricarbonyl tamoxifen can be synthesized in-house in radiopharmacy lab. Radionuclide therapy with Re-188-tricarbonyl tamoxifen can be given using 10 times less amount of tamoxifen as compared to cold tamoxifen.

Mutually distinguishing microRNA signatures of breast, ovarian and endometrial cancers in vitro

Early diagnosis and therapy in the first stages of a malignant disease is the most crucial factor for successful cancer treatment and recovery. Currently, there is a high demand for novel diagnostic tools that indicate neoplasms in the first or pre‑malignant stages. MicroRNAs (miRNA or miR) are small non‑coding RNAs that may act as oncogenes and downregulate tumor‑suppressor genes. The detection and mutual discrimination of the three common female malignant neoplasia types breast (BC), ovarian (OC) and endometrial cancer (EC) could be enabled by identification of tumor entity‑specific miRNA expression differences. In the present study, the relative expression levels of 25 BC, EC and OC‑related miRNAs were assessed by reverse transcription‑quantitative PCR and determined using the 2‑ΔΔCq method for normalization against the mean of four housekeeping genes. Expression levels of all miRNAs were analyzed by regression against cell line as a factor. An expression level‑based discrimination between BC and OC cell types was obtained for a subgroup of ten different miRNA types. miR‑30 family genes, as well as three other miRNAs, were found to be uniformly upregulated in OC cells compared with BC cells. BC and EC cells could be distinguished by the expression profiles of six specific miRNAs. In addition, four miRNAs were differentially expressed between EC and OC cells. In conclusion, miRNAs were identified as a potential novel tool to detect and mutually discriminate between BC, OC and EC. Based on a subset of 25 clinically relevant human miRNA types, the present study could significantly discriminate between these three female cancer types by means of their expression levels. For further verification and validation of miRNA‑based biomarker expression signatures that enable valuable tumor detection and characterization in routine screening or potential therapy monitoring, additional and extended in vitro analyses, followed by translational studies utilizing patients' tissue and liquid biopsy materials, are required.

Potential role of estradiol in ovariectomy-induced derangement of renal endocrine functions

Menopause is an important physiological event associated with structural and functional changes in the kidneys. An animal model of bilateral ovariectomy was used to study the effects of estrogen depletion, replacement and antiestrogen on renal structure and endocrine function. Sixty female rats were divided into six groups; group I was the control group, the remaining five groups underwent ovariectomy: group II received no treatment. The other groups received estradiol in group III, tamoxifen in group IV, estradiol followed by tamoxifen in group V and tamoxifen followed by estradiol in group VI. Serum creatinine, blood urea nitrogen, and endocrine functions of kidney were measured. Tissue samples were examined both microscopically for beta estrogen receptors and ultrastructurally for cell changes. Groups II, IV & VI showed a significant increase in creatinine, blood urea nitrogen, renal malondialdehyde, renal erythropoietin, plasma renin and plasma prostaglandin E2 and a significant decrease in renal antioxidants and serum vitamin D3. Groups III &V had a significant decrease in creatinine, blood urea nitrogen, renal malondialdehyde and renal erythropoietin with an increase in renal antioxidants, plasma prostaglandin E2 and serum vitamin D3. Histopathological and ultrastructural examinations revealed atrophic tubular changes in group II. The changes were less marked in groups III &V and more extensive in groups IV & VI. Estrogen receptor beta staining showed progressively increased expression in the absence of estrogen. Structural and most endocrine functions of the kidney were significantly affected by estradiol deficiency. Estradiol replacement exhibited a protective effect on renal tissue and endocrine functions.

Nanotamoxifen Delivery System: Toxicity Assessment After Oral Administration and Biodistribution Study After Intravenous Delivery of Radiolabeled Nanotamoxifen

Tamoxifen is the most prescribed anticancer oral drug for increasing overall survival and decreasing recurrence and the risk of contralateral disease. However, some side effects, such as endometrial and liver tumors, thromboembolic disorders, and drug resistance, are associated with long-term tamoxifen treatment. We assessed the hematologic and organ toxicity after oral administration of three different doses of nanotamoxifen formulations. We also performed biodistribution studies of Technetium-99m ((99m)Tc)-nanotamoxifen after intravenous administration. The results demonstrated that nanotamoxifen was well-tolerated, with no adverse effect on biochemical parameters of blood and at the cellular level. Nitric oxide (NO) levels indicated no free radical formation. Oral nanotamoxifen is well-tolerated, with no hepatic or renal toxicity. Intravenous nanotamoxifen has potential to escape the liver, and is known for producing the harmful metabolite 4-hydroxytamoxifen (4OH-tamoxifen), which can cause uterine cancer.