Platinum based radiochemotherapies: Free radical mechanisms and radiotherapy sensitizers

Recent Developments in the Study of the Microenvironment of Cancer and Drug Delivery

Cancer is characterized by disrupted molecular variables caused by cells that deviate from regular signal transduction. The uncontrolled segment of such cancerous cells annihilates most of the tissues that contact them. Gene therapy, immunotherapy, and nanotechnology advancements have resulted in novel strategies for anticancer drug delivery. Furthermore, diverse dispersion of nanoparticles in normal stroma cells adversely affects the healthy cells and disrupts the crosstalk of tumour stroma. It can contribute to cancer cell progression inhibition and, conversely, to acquired resistance, enabling cancer cell metastasis and proliferation. The tumour's microenvironment is critical in controlling the dispersion and physiological activities of nano-chemotherapeutics which is one of the targeted drug therapy. As it is one of the methods of treating cancer that involves the use of medications or other substances to specifically target and kill off certain subsets of malignant cells. A targeted therapy may be administered alone or in addition to more conventional methods of care like surgery, chemotherapy, or radiation treatment. The tumour microenvironment, stromatogenesis, barriers and advancement in the drug delivery system across tumour tissue are summarised in this review.

Integrating the microneedles with carboplatin to facilitate the therapeutic effect of radiotherapy for skin cancers

In most skin cancer patients, excisional surgery is required to remove tumorous tissue. However, the risk of locoregional recurrence after surgery alone is relatively high, particularly for a locally advanced stage of melanoma. Therefore, additional adjuvant treatments, such as radiotherapy, can be used after surgery to inhibit recurrent melanoma after surgical removal. To enhance local radiotherapy, we present the combined X-ray radiation and radiosensitizers (carboplatin) through microneedles (MNs) to treat melanoma. The MNs could be beneficial to precisely delivering carboplatin into the sub-epidermal layer of the melanoma region and alleviate patients' fear and discomfort during the drug administration compared to the traditional local injection. The carboplatin was loaded into the tips of dissolving gelatin MNs (carboplatin-MNs) through the molding method. The results show gelatin MNs have sufficient mechanical strength and can successfully administer carboplatin into the skin. Both in vitro and in vivo studies suggest that carboplatin can enhance radiotherapy in melanoma treatment. With a combination of radiotherapy and carboplatin, the inhibition effect of carboplatin delivered into the B16F10 murine melanoma model through MNs administration (1.2 mg/kg) is equivalent to that through an intravenous route (5 mg/kg). The results demonstrate a promise of combined carboplatin and X-ray radiation treatment in treating melanoma by MNs administration.

Frontier progress of the combination of modern medicine and traditional Chinese medicine in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC, accounting for 90% of primary liver cancer) was the sixth most common cancer in the world and the third leading cause of cancer death in 2020. The number of new HCC patients in China accounted for nearly half of that in the world. HCC was of occult and complex onset, with poor prognosis. Clinically, at least 15% of patients with HCC had strong side effects of interventional therapy (IT) and have poor sensitivity to chemotherapy and targeted therapy. Traditional Chinese medicine (TCM), as a multi-target adjuvant therapy, had been shown to play an active anti-tumor role in many previous studies. This review systematically summarized the role of TCM combined with clinically commonly used drugs for the treatment of HCC (including mitomycin C, cyclophosphamide, doxorubicin, 5-fluorouracil, sorafenib, etc.) in the past basic research, and summarized the efficacy of TCM combined with surgery, IT and conventional therapy (CT) in clinical research. It was found that TCM, as an adjuvant treatment, played many roles in the treatment of HCC, including enhancing the tumor inhibition, reducing toxic and side effects, improving chemosensitivity and prolonging survival time of patients. This review summarized the advantages of integrated traditional Chinese and modern medicine in the treatment of HCC and provides a theoretical basis for clinical research.

Mössbauer effect using 57Fe-ferrabisdicarbollide ([o-57FESAN]-): a glance into the potential of a low-dose approach for glioblastoma radiotherapy

Although a variety of cancers is initially susceptible to chemotherapy, they eventually develop multi-drug resistance. To overcome this situation, more effective and selective treatments are necessary by using anti-tumour agents...

Generic Anticancer Drugs of the Jan Aushadhi Scheme in India and Their Branded Counterparts: The First Cost Comparison Study

Introduction: In India, the costs of cancer drugs are exorbitant and cause significant financial toxicity to the affected patient and their family members. Considering this, Jan Aushadhi pharmacy stores were established across the country by the government of India with the objective of providing cheap generic medicines to patients. The objective of this study was to perform a cost comparison study of generic chemotherapeutic drugs provided through Jan Aushadhi pharmacies versus their branded counterparts. This will help patients and physicians get first-hand information on the cost variation between generic and branded anticancer drugs in India.

Materials and Methods: The cost of Jan Aushadhi generic drugs and the cost of the most expensive and cheapest marketed branded drugs for the same molecule and dose were ascertained and presented in both Indian Rupees (INR) and US Dollars (as of July 2021). Finally, the difference in costs in INR, cost ratio, and cost variance were calculated, comparing the price of the Jan Aushadhi generic drugs with the most expensive and the cheapest branded drug in the same category.

Results: Compared to branded drugs, all the Jan Ausadhi generic drugs were cheaper, except one (methotrexate). The highest cost difference was observed for docetaxel, while the least was observed for methotrexate tablets (2.5 mg). The highest cost ratio (22.24) and cost variance (3327.56) were observed for doxorubicin injection (50 mg).

Conclusion: The current study compares the cost difference between the marketed branded and Jan Aushadhi generic anticancer drugs for the first time. Replacing the costly branded anticancer drugs with Jan Aushadhi generic drugs can result in substantial cost savings. The information obtained from this cost difference analysis will be helpful for the healthcare fraternity, patients, policymakers, and society at large.

A pH-responsive Pt-based nanoradiosensitizer for enhanced radiotherapy via oxidative stress amplification

Tumor radioresistance is a major issue in radiotherapy. To address it, a pH-responsive nanoradiosensitizer was synthesized employing a simple method. Initially, chloroplatinic acid was reduced by human serum albumin (HSA) to form HSA-wrapped Pt@HSA nanoparticles (NPs). Subsequently, cinnamicaldehyde (CA) was grafted on Pt@HSA via aldimine condensation to obtain nanoradiosensitizer Pt@HSA/CA NPs. CA would be released in tumor cells (pH = 5.5) to induce the production of reactive oxygen species, including H₂O₂, ˙OH, etc. The increased decomposition of H₂O₂ catalyzed by the NPs resulted in enhanced production of oxygen, leading to hypoxia relief of the tumor cells, which is beneficial for radiotherapy. Due to the high X-ray attenuation coefficient of Pt, Pt@HSA/CA NPs enhance the energy deposition of radiation. Cytotoxicity assay revealed that Pt@HSA/CA NPs resulted in a cell death rate of 77%, which was 24.4% higher than that of Pt@HSA NPs even under low-dose X-ray irradiation of 4 Gy. Colony formation assay demonstrated that the sensitization enhancement ratio was 1.37, indicating that Pt@HSA/CA NPs displayed remarkable radiosensitizing ability. Notably, in vivo results indicated that the NPs could increase the tumor inhibition rate to 91.2% with negligible side effects to normal tissues. These results demonstrate that Pt@HSA/CA NPs had outstanding tumor curative efficacy and hypotoxicity.

An assessment of serum oxidative stress and antioxidant parameters in patients undergoing treatment for cervical cancer

OBJECTIVES

Oxidative stress and antioxidants are involved in all aspects of cervical cancer. The present study evaluated serum levels of oxidative stress and antioxidant biomarkers in cervical cancer patients and healthy controls. Moreover, the effect of Concurrent chemoradiotherapy (CCRT) on these biomarkers and their association with treatment outcome was investigated.

DESIGN

This study included ninety-seven cervical cancer patients and thirty controls. Three oxidative stress parameters (8-hydroxy-2-deoxyguanosine, Protein Carbonyl, and Malondialdehyde) and four antioxidant parameters (Superoxide Dismutase, Catalase, Glutathione Peroxidase, and Total Antioxidant Status) were measured. The analysis was conducted using repeated measures ANOVA for comparing among the phases (before, during, and follow-up) of treatment. The control group was compared using the Dunnet test. Logistic regression analysis was also conducted between oxidative stress and antioxidant parameters to study their association.

RESULTS

Significant rises in oxidative damage markers were observed in cervical cancer patients of all stages, compared to controls. There was a further increase in oxidative stress markers during CCRT among complete responders. However, among non-responders, the oxidative stress biomarkers like Protein Carbonyl and Malondialdehyde were unaltered during CCRT. Simultaneously, there was a significant decrease in antioxidant parameters in cervical cancer patients of all stages compared to controls. During CCRT, antioxidant levels continuously depleted among complete responders. Nevertheless, in non-responders, antioxidant parameters like Superoxide Dismutase and Total Antioxidant Status were consistent. The oxidative stress markers and antioxidant parameters normalized among complete responders at six months follow up. While in non-responders, the normalization of these parameters was not observed.

CONCLUSION

Our results indicate that increased oxidative stress and diminished antioxidants among patients were associated with carcinoma cervix. Induced oxidative stress and decreased antioxidant parameters during CCRT among the complete responders show the treatment's efficacy. Oxidant-antioxidant profile merits investigation as markers of diagnosis, treatment response, survival, and recurrence in extensive prospective studies.

Addition of Platinum Derivatives to Fluoropyrimidine-Based Neoadjuvant Chemoradiotherapy for Stage II/III Rectal Cancer: Systematic Review and Meta-Analysis

BACKGROUND

Current guidelines recommend neoadjuvant therapy for patients with stage II or III rectal cancer. The addition of platinum derivatives to fluoropyrimidine-based chemoradiotherapy has been frequently investigated, but their role in this setting remains controversial.

METHODS

PubMed, Cochrane Library, and Web of Science were systematically searched for randomized trials comparing chemoradiotherapy with or without platinum agents in stage II or III rectal cancer. Main outcome parameters were overall and disease-free survival, additional outcomes included pathological complete response, isolated local recurrence, distant recurrence, toxicity, and perioperative morbidity. Time-to-event data were pooled as hazard ratios (HRs) by the inverse variance method and binary outcomes as odds ratios (ORs) by the Peto method with their respective 95% confidence interval (CI). All statistical tests were two-sided.

RESULTS

Ten randomized controlled trials with data on 5599 patients were included in the meta-analysis. Platinum derivatives did not statistically significantly improve overall survival (HR = 0.93, 95% CI = 0.82 to 1.05, P = .23), disease-free survival (HR = 0.91, 95% CI = 0.83 to 1.01, P = .07), or local recurrence (OR = 0.83, 95% CI = 0.66 to 1.05, P = .12). However, it led to a statistically significant increase of pathological complete response (OR = 1.31, 95% CI = 1.10 to 1.55, P = .002) and a statistically significant reduction of distant recurrence (OR = 0.78, 95% CI = 0.66 to 0.92, P = .004). Benefits were accompanied by higher rates of grade 3 or 4 toxicities.

CONCLUSIONS

Intensified neoadjuvant chemoradiotherapy with the addition of platinum derivatives cannot be recommended routinely because it did not improve overall or disease-free survival and was associated with increased toxicity. It needs to be elucidated whether the benefits in distant recurrence and pathological complete response may be advantageous for selected high-risk patients.

Mechanism of HN‑3 cell apoptosis induced by carboplatin: Combination of mitochondrial pathway associated with Ca2+ and the nucleus pathways

Laryngeal carcinomas have been recognized as a serious health threat worldwide. In the present study, the mechanism of apoptosis in HN-3 cells induced by carboplatin (CBCDA), a widely used anti-cancer drug, was investigated. The pro-apoptotic effect of CBCDA in HN-3 cells was demonstrated to be time- and dose-dependent. Therefore, the stages of apoptosis were investigated in chronological order. The results demonstrated that excessive generation of cytosolic Ca²⁺ in HN-3 cells was initially triggered when cells were exposed to CBCDA, followed by the appearance of mitochondrial depolarization and oxidative stress, leading to the release of apoptosis-inducing factor. At later stages, expression of caspase-8 was increased due to the apoptotic signals originating from CBCDA-induced DNA damage, as well as caspase-9 and poly ADP ribose polymerase (PARP) expression upregulation. Glutathione decreased the available CBDCA concentration, decreased apoptosis and alleviating oxidative stress, thus reducing the actual effective concentration. Mechanistic research may benefit the rational design of more efficient therapeutic strategies as well as development of novel platinum-based agents.

The Role of Tumor Microenvironment in Chemoresistance: To Survive, Keep Your Enemies Closer

Chemoresistance is a leading cause of morbidity and mortality in cancer and it continues to be a challenge in cancer treatment. Chemoresistance is influenced by genetic and epigenetic alterations which affect drug uptake, metabolism and export of drugs at the cellular levels. While most research has focused on tumor cell autonomous mechanisms of chemoresistance, the tumor microenvironment has emerged as a key player in the development of chemoresistance and in malignant progression, thereby influencing the development of novel therapies in clinical oncology. It is not surprising that the study of the tumor microenvironment is now considered to be as important as the study of tumor cells. Recent advances in technological and analytical methods, especially ‘omics’ technologies, has made it possible to identify specific targets in tumor cells and within the tumor microenvironment to eradicate cancer. Tumors need constant support from previously ‘unsupportive’ microenvironments. Novel therapeutic strategies that inhibit such microenvironmental support to tumor cells would reduce chemoresistance and tumor relapse. Such strategies can target stromal cells, proteins released by stromal cells and non-cellular components such as the extracellular matrix (ECM) within the tumor microenvironment. Novel in vitro tumor biology models that recapitulate the in vivo tumor microenvironment such as multicellular tumor spheroids, biomimetic scaffolds and tumor organoids are being developed and are increasing our understanding of cancer cell-microenvironment interactions. This review offers an analysis of recent developments on the role of the tumor microenvironment in the development of chemoresistance and the strategies to overcome microenvironment-mediated chemoresistance. We propose a systematic analysis of the relationship between tumor cells and their respective tumor microenvironments and our data show that, to survive, cancer cells interact closely with tumor microenvironment components such as mesenchymal stem cells and the extracellular matrix.