Radiotherapy and radiosensitization in breast cancer: Molecular targets and clinical applications

PLK4 as a potential target to enhance radiosensitivity in triple-negative breast cancer

Radioresistance is one of the barriers to developing more effective therapies against the most aggressive, triple-negative, breast cancer (TNBC) subtype. In our previous studies, we showed that inhibition of Polo-like Kinase 4 (PLK4) by a novel drug, CFI-400945 significantly enhances the anticancer effects of radiotherapy (RT) compared to single treatment alone. Here we further investigate the role of PLK4 in enhancing radiation effects in TNBC and explore mechanisms of PLK4 inhibition and radiation combinatorial antiproliferative effects. To assess cellular proliferation in response to treatments, we used colony formation assays in TNBC cell lines and patient-derived organoids (PDOs). Downregulation of PLK4 expression was achieved using siRNA silencing in TNBC cell lines. Immunofluorescence against centrin was used to assess the alteration of centriole amplification in response to treatments. We observed that inhibition of PLK4 by CFI-400945 or Centrinone B or its downregulation by siRNA, when combined with RT, resulted in a significant increase in antiproliferative effect in TNBC cells lines and PDOs compared to untreated or single-treated cells. Anticancer synergy was observed using a response matrix in PDOs treated with CFI-400945 and RT. We show that the overamplification of centrioles might be involved in the combined antiproliferative action of RT and PLK4 inhibition. Our data suggest that PLK4 is a promising target for enhancing the anticancer effects of RT in TNBC that, at least in part, is modulated by the overamplification of centrioles. These results support further mechanistic and translational studies of anti-PLK4 agents and RT as an anticancer combination treatment strategy.

Wogonin Diminishes Radioresistance of Breast Cancer via Inhibition of the Nrf2/HIF-1[Formula: see text] Pathway

Radiotherapy plays a crucial role in the multimodal treatment of breast cancer. However, radioresistance poses a significant challenge to its effectiveness, hindering successful cancer therapy. Emerging evidence indicates that Nrf2 and HIF-1[Formula: see text] are critical regulators of cellular anti-oxidant responses and that their overexpression significantly promotes radioresistance. Wogonin (WG), the primary component isolated from Scutellaria baicalensis, exhibits potential antitumor and reversal of multidrug resistance activities. Nevertheless, the role of WG in radioresistance remains unclear. This study aims to explore the effects of WG on the radioresistance of breast cancer. Our results indicate that Nrf2 and HIF-1[Formula: see text] overexpression was observed in breast cancer tissues and was correlated with the histological grading of the disease. Radiation further increased the levels of Nrf2 and HIF-1[Formula: see text] in breast cancer cells. However, WG demonstrated the ability to induce cell apoptosis and reverse radioresistance by inhibiting the Nrf2/HIF-1[Formula: see text] pathway. These effects were also confirmed in xenograft mice models. Mechanistically, WG enhanced the level of the Nrf2 inhibitor Keap1 through reducing CpG methylation in the promoter region of the Keap1 gene. Consequently, the Nrf2/HIF-1[Formula: see text] pathway, along with the Nrf2- and HIF-1[Formula: see text]-dependent protective responses, were suppressed. Taken together, our findings demonstrate that WG can epigenetically regulate the Keap1 gene, inhibit the Nrf2/HIF-1[Formula: see text] pathway, induce apoptosis in breast cancer cells, and diminish acquired radioresistance. This study offers potential strategies to overcome the limitations of current radiotherapy for breast cancer.

Dysregulated Stem Cell Markers Musashi-1 and Musashi-2 are Associated with Therapy Resistance in Inflammatory Breast Cancer

BACKGROUND AND AIM

While preliminary evidence points to pro-tumorigenic roles for the Musashi (MSI) RNA-binding proteins Musashi-1 (MSI1) and Musashi-2 (MSI2) in some breast cancer subtypes, no data exist for inflammatory breast cancer (IBC).

METHODS

MSI gene expression was quantified in IBC SUM149PT cells. We then used small interfering RNA-based MSI1 and MSI2 double knockdown (DKD) to understand gene expression and functional changes upon MSI depletion. We characterized cancer stem cell characteristics, cell apoptosis and cell cycle progression via flow cytometry, mammospheres via spheroid assays, migration and proliferation via digital holographic microscopy, and cell viability using BrdU assays. Chemoresistance was determined for paclitaxel and cisplatin with MTT assays and radioresistance was assessed with clonogenic analyses. In parallel, we supported our in vitro data by analyzing publicly available patient IBC gene expression datasets.

RESULTS

MSI1 and MSI2 are upregulated in breast cancer generally and IBC specifically. MSI2 is more commonly expressed compared to MSI1. MSI DKD attenuated proliferation, cell cycle progression, migration, and cell viability while increasing apoptosis. Stem cell characteristics CD44(+)/CD24(-), TERT and Oct4 were associated with MSI expression in vivo and were decreased in vitro after MSI DKD as was ALDH expression and mammosphere formation. In vivo, chemoresistant tumors were characterized by MSI upregulation upon chemotherapy application. In vitro, MSI DKD was able to alleviate chemo- and radioresistance.

CONCLUSIONS

The Musashi RNA binding proteins are dysregulated in IBC and associated with tumor proliferation, cancer stem cell phenotype, chemo- and radioresistance. MSI downregulation alleviates therapy resistance and attenuates tumor proliferation in vitro.

Reprogramming of the tumor microenvironment using a PCN-224@IrNCs/D-Arg nanoplatform for the synergistic PDT, NO, and radiosensitization therapy of breast cancer and improving anti-tumor immunity

The low X-ray attenuation coefficient of tumor soft tissue and the hypoxic tumor microenvironment (TME) during radiation therapy (RT) of breast cancer result in RT resistance and thus reduced therapeutic efficacy. In addition, immunosuppression induced by the TME severely limits the antitumor immunity of radiation therapy. In this paper, we propose a PCN-224@IrNCs/D-Arg nanoplatform for the synergistic radiosensitization, photodynamic, and NO therapy of breast cancer that also boosts antitumor immunity (PCN = porous coordination network, IrNCs = iridium nanocrystals, D-Arg = D-arginine). The local tumors can be selectively ablated via reprogramming the tumor microenvironment (TME), photodynamic therapy (PDT) and NO therapy, and the presence of the high-Z element Ir that sensitizes radiotherapy. The synergistic execution of these treatment modalities also resulted in adapted antitumor immune response. The intrinsic immunomodulatory effects of the nanoplatform also repolarize macrophages toward the M1 phenotype and induce dendritic cell maturation, activating antitumor T cells to induce immunogenic cell death as demonstrated in vitro and in vivo. The nanocomposite design reported herein represents a new regimen for the treatment of breast cancer through TME reprogramming to exert a synergistic effect for effective cancer therapy and antitumor immunity.

Effect of exercise on rehabilitation of breast cancer surgery patients: A systematic review and meta-analysis of randomized controlled trials

AIM

To determine the effective exercise methods for different complications of breast cancer patients after surgery.

DESIGN

Systematic review and meta-analysis.

METHODS

A comprehensive electronic search was carried out with no time limit until May 2020. Studies must have been randomized controlled trials of patients after breast cancer surgery, without limit to the way of exercise. Literature quality was evaluated by the modified Jadad scale. The meta-analysis was conducted with CMA2.0 software.

RESULTS

Aerobic exercise reduced the intensity of the pain (MD = -1.043), improved shoulder flexion (MD = 3.398) and internal rotation range (MD = 3.868), lessened upper limb dysfunction (MD = -5.231) and improved muscle strength during flexion (MD = 1.076) and abduction (MD = 0.991). Shoulder elbow movement improved the range of shoulder external rotation (MD = 2.691) and reduced the incidence of arm lymphedema (RR = 0.343). Anti-resistance exercise also lessened upper limb dysfunction (MD = - 4.094).

A Review on the Use of Gold Nanoparticles in Cancer Treatment

According to a 2020 WHO study, cancer is responsible for one in every six fatalities. One in four patients die due to side effects and intolerance to chemotherapy, making it a leading cause of patient death. Compared to traditional tumor therapy, emerging treatment methods, including immunotherapy, gene therapy, photothermal therapy, and photodynamic therapy, have proven to be more effective. The aim of this review is to highlight the role of gold nanoparticles in advanced cancer treatment. A systematic and extensive literature review was conducted using the Web of Science, PubMed, EMBASE, Google Scholar, NCBI, and various websites. Highly relevant literature from 141 references was chosen for inclusion in this review. Recently, the synergistic benefits of nano therapy and cancer immunotherapy have been shown, which could allow earlier diagnosis, more focused cancer treatment, and improved disease control. Compared to other nanoparticles, the physical and optical characteristics of gold nanoparticles appear to have significantly greater effects on the target. It has a crucial role in acting as a drug carrier, biomarker, anti-angiogenesis agent, diagnostic agent, radiosensitizer, cancer immunotherapy, photodynamic therapy, and photothermal therapy. Gold nanoparticle-based cancer treatments can greatly reduce current drug and chemotherapy dosages.

Effectiveness of three exercise programs and intensive follow-up in improving quality of life, pain, and lymphedema among breast cancer survivors: a randomized, controlled 6-month trial

PURPOSE

Postoperative complications of breast cancer (BC) seriously affect the quality of life (QOL) of survivors. Physical activity is related to prevention of complications and improvement of QOL. Follow-up can keep patients motivated to exercise. This study aimed to (1) compare the effect of three exercise programs on lymphedema, pain, and QOL in BC patients and (2) explore the effect of intensive follow-up on the outcomes of exercise programs.

METHODS

A single-blind randomized parallel controlled trial with a 6-month intervention was carried out in China in 2021. The study sample included 200 women with BC. The patients were randomly divided into 4 groups. G₀ (control group) was joint mobility exercise (JME) group; G₁ was joint mobility exercise + intensive follow-up (IF) group; G₂ was JME + aerobic exercise (AE) + IF group; and G₃ was JME + progressive resistance exercise (PRE) + IF group. Outcome measures were evaluated at baseline (T₁), 3 months post-intervention (T₂), and 6 months post-intervention (T₃). The following instruments and measurements were administered before and after the intervention: the Functional Assessment of Cancer Therapy-Breast (FACT-B) instrument, the numerical rating scale (NRS), and the relative volume change (RVC). Verificating aim 1 is by comparing the results of G₁, G₂, and G₃, and verificating aim 2 is achieved by comparing G₀ and G₁. Differences before and after the intervention were determined by analysis of variance of repeated measures and Kruskal-Wallis nonparametric analysis of variance.

RESULTS

Among the exercise programs, JME + PRE + IF resulted in the best improvement in QOL (T2: ΔG₃-G₀ = 13.032, P = 0.008; T2: ΔG₃-G₁ = 13.066, P < 0.001; ΔG₃-G₀ = 17.379, P < 0.001). For pain relief, JME + AE + IF had the best improvement (T3: ΔG₂-G₁ =  - 0.931, P = 0.010; ΔG₂-G₀ =  - 1.577, P < 0.001). For the prevention of lymphedema, JME + AE + IF (Z = 2.651, P = 0.048) and JME + PRE + IF (Z = 3.277, P = 0.006) had the similar effect, but JME + PRE + IF is better than JME + AE + IF.

CONCLUSION

JME + PRE have the best effect in improving the QOL and preventing lymphedema after surgery. In improving pain, the effect of JME + AE appears earlier, and the overall effect of JME + PRE is better. In addition, long-term and planned monitoring and follow-up are also important.