The intensity of radiotherapy-elicited immune response is associated with esophageal cancer clearance. J Immunol Res. 2014;2014:794249. [PMID: 24967419 PMCID: PMC4055126 DOI: 10.1155/2014/794249]

Neutrophil‑to‑lymphocyte ratio reflects lung injury in thoracic radiotherapy and immune checkpoint inhibitors combination therapy with different sequences

The combination of thoracic radiotherapy and immune checkpoint inhibitors (ICIs) has emerged as a novel treatment approach for malignant tumors. However, it is important to consider the potential exacerbation of lung injury associated with this treatment modality. The neutrophil-to-lymphocyte ratio (NLR), an inflammatory marker, holds promise as a non-invasive indicator for assessing the toxicity of this combination therapy. To investigate this further, a study involving 80 patients who underwent thoracic radiotherapy in conjunction with ICIs was conducted. These patients were divided into two groups: The concurrent therapy group and the sequential therapy group. A logistic regression analysis was conducted to ascertain risk factors for grade ≥2 pneumonitis. Following propensity score matching, the NLR values were examined between the concurrent group and the sequential group to evaluate any disparity. A mouse model of radiation pneumonitis was established, and ICIs were administered at varying time points. The morphological evaluation of lung injury was conducted using H&E staining, while the NLR values of peripheral blood were detected through flow cytometry. Logistic regression analysis revealed that radiation dosimetric parameters (mean lung dose, total dose and V20), the inflammatory index NLR at the onset of pneumonitis, and treatment sequences (concurrent or sequential) were identified as independent predictors of grade ≥2 treatment-related pneumonitis. The results of the morphological evaluation indicated that the severity of lung tissue injury was greater in cases where programmed cell death protein 1 (PD-1) blockade was administered during thoracic radiotherapy, compared with cases where PD-1 blockade was administered 14 days after radiotherapy. Moreover, the present study demonstrated that the non-invasive indicator known as the NLR has the potential to accurately reflect the aforementioned injury.

The current understanding of the immune landscape relative to radiotherapy across tumor types

Radiotherapy is part of the standard of care treatment for a great majority of cancer patients. As a result of radiation, both tumor cells and the environment around them are affected directly by radiation, which mainly primes but also might limit the immune response. Multiple immune factors play a role in cancer progression and response to radiotherapy, including the immune tumor microenvironment and systemic immunity referred to as the immune landscape. A heterogeneous tumor microenvironment and the varying patient characteristics complicate the dynamic relationship between radiotherapy and this immune landscape. In this review, we will present the current overview of the immunological landscape in relation to radiotherapy in order to provide insight and encourage research to further improve cancer treatment. An investigation into the impact of radiation therapy on the immune landscape showed in several cancers a common pattern of immunological responses after radiation. Radiation leads to an upsurge in infiltrating T lymphocytes and the expression of programmed death ligand 1 (PD-L1) which can hint at a benefit for the patient when combined with immunotherapy. In spite of this, lymphopenia in the tumor microenvironment of 'cold' tumors or caused by radiation is considered to be an important obstacle to the patient's survival. In several cancers, a rise in the immunosuppressive populations is seen after radiation, mainly pro-tumoral M2 macrophages and myeloid-derived suppressor cells (MDSCs). As a final point, we will highlight how the radiation parameters themselves can influence the immune system and, therefore, be exploited to the advantage of the patient.

The molecular basis of immuno-radiotherapy

PURPOSE

Radiotherapy (RT) and immunotherapy are powerful anti-tumor treatment modalities. Experimental research has demonstrated an important interplay between the cytotoxic effects of RT and the immune system. This systematic review provides an overview of the basics of anti-tumor immunity and focuses on the mechanisms underlying the interplay between RT and immune anti-tumor response that set the molecular basis of immuno-RT.

CONCLUSIONS

An 'immunity acquired equilibrium' mimicking tumor dormancy can be achieved post-irradiation treatment, with the balance shifted toward tumor eradication or regrowth when immune cells' cytotoxic effects or cancer proliferation rate prevail, respectively. RT has both immunosuppressive and immune-enhancing properties. The latter effect is also known as radio-vaccination. Its mechanisms involve up- or down-regulation of membrane molecules, such as PD-L1, HLA-class-I, CD80/86, CD47, and Fas/CD95, that play a vital role in immune checkpoint pathways and increased cytokine expression (e.g. INFα,β,γ, IL1,2, and TNFα) by cancer or immune cells. Moreover, the interactions of radiation with the tumor microenvironment (fibroblasts, tumor-infiltrating lymphocytes, monocytes, and dendritic cells are also an important component of radio-vaccination. Thus, RT may have anti-tumor vaccine properties, whose sequels can be exploited by immunotherapy agents to treat different cancer subtypes effectively.

Dysfunction of apoptosis and autophagy correlates with local recurrence in esophageal squamous cell carcinoma after definitive chemoradiation

OBJECTIVE

Definitive chemoradiotherapy (dCRT) is one of the standard treatments for esophageal squamous cell carcinoma (ESCC), but local recurrence is the main cause of treatment failure. The changes in apoptosis and autophagy in recurrent tumors of patients with ESCC following dCRT have been poorly estimated. Thus, this study aimed to investigate the expressions of key regulators of apoptosis and autophagy in matched paired samples of primary and recurrent ESCC.

METHODS

The medical records of patients with locally advanced ESCC who developed local recurrence after dCRT were reviewed, and the expression profiling of apoptosis-related genes, cell apoptosis, autophagy and autophagy-related proteins were detected in normal esophageal squamous epithelium and paired samples of primary and recurrent ESCC.

RESULTS

A total of 126 patients were enrolled, and 52.4% of them had stage III disease. The 1-, 3- and 5-year local recurrence-free survival (LRFS) rates were 54.8, 19.8 and 14.3%, respectively, with a median LRFS of 13.0 months. Patients with T2 tumor or stage II disease showed a significantly prolonged LRFS compared with that of patients with T3-4 tumor or stage III disease. The Apoptotic Machinery key genes expression profiling identified 5 upregulated and 7 downregulated apoptosis-related genes in recurrent tumors compared with their expression levels in the matched primary ESCC tumors. High expression of CD40, TRAF4 and BCL2A1, and low expression of CARD6 and TNFRSF21 were associated with increased risk of early local recurrence after dCRT. No differences in apoptotic index between primary and recurrent samples were detected. However, typical morphological features of autophagosomes and elevated LC3-II protein expression were detected in recurrent tumor samples, and positive LC3-II expression was correlated with increased risk of early local recurrence.

CONCLUSION

Our findings indicated that apoptosis and autophagy dysfunction correlated with early local recurrence in patients with locally advanced ESCC receiving dCRT. Further studies are necessary to understand the biology of tumor recurrence in esophageal cancer.

Infiltrative tumour growth pattern correlates with poor outcome in oesophageal cancer

Objective

Oesophageal cancer (OEC) is an aggressive disease with a poor survival rate. Prognostic markers are thus urgently needed. Due to the demonstrated prognostic value of histopathological growth pattern (HGP) in other cancers, we performed a retrospective assessment of HGP in patients suffering from invasive OEC.

Design

A first cohort composed of 89 treatment-naïve operated patients with OEC from The Cancer Genome Atlas (TCGA) public database was constituted, from which H&E images and RNA-sequencing data were retrieved. Next, a second cohort composed of 99 patients with OEC treated and operated in a Belgian hospital was established. H&E-stained sections and extracted tumorous RNA were obtained from the samples. HGP were assessed on H&E slides as infiltrative (IGP) or expansive (EGP). TCGA RNA-sequencing data were analysed through the gene set enrichment analysis and Cytoscape softwares. Real-time quantitative PCR (qPCR) experiments were performed to assess gene expression in the Belgian cohort.

Results

IGP patients displayed a grim prognosis compared with EGP patients, while IGP was found as associated with numerous lymphovascular emboli and perinervous infiltrations. Analyses of the TCGA expression data showed that angiogenesis, epithelial-to-mesenchymal transition (EMT) and inflammation were significantly upregulated in IGP compared with EGP samples. qPCR experiments of three genes appearing as highly upregulated in each pathway showed no difference in expression according to the HGP.

Conclusion

The current study demonstrates the poor prognostic value carried by IGP in OC and suggests angiogenesis, EMT and inflammation as key carcinogenetic pathways upregulated in this pattern.

Immune surveillance activation after neoadjuvant therapy for esophageal adenocarcinoma and complete response

After neoadjuvant chemoradiotherapy for esophageal adenocarcinoma, up to 29% of patients have a pathological complete response (pCR). What to do afterward is still under debate. The aim of this prospective study was to define which local markers of immune response might act as predictors of pCR and of recurrence after pCR. The peritumoral healthy mucosa of the surgical specimen was sampled at esophagectomy and analyzed by immunohistochemistry, flow cytometry and Real-Time PCR. One hundred and twenty-three patients received neoadjuvant therapy for esophageal adenocarcinoma and were included in the study. Significantly higher rate of natural killer (NK) cells (CD57+), intraepithelial CD8 + T lymphocytes and degranulating T- and NK-cells (CD107+) were observed in the healthy mucosa of patients with pCR. Moreover, pCR was characterized by a lower immune-check points gene expression level. T-cell activation markers mRNA levels were significantly lower in patients with pCR and recurrent disease, showing an excellent accuracy in the prediction of the postoperative recurrence. Costimulatory molecules mRNA relative levels tended to be lower in patients with pCR and recurrent disease, showing a good accuracy in the prediction of postoperative recurrence in patients with pCR. The immune profile identified in this study might further be tested in large prospective trials as marker of pCR after neoadjuvant therapy and as predictor of recurrence after pCR.

Elevated VEGF-A & PLGF concentration in aqueous humor of patients with uveal melanoma following Iodine-125 plaque radiotherapy

AIM

To measure the concentration of vascular endothelial growth factor-A (VEGF-A), and placental growth factor (PLGF) in aqueous humor of uveal melanoma patients before and after Iodine-125 plaque therapy (IPT), determine the postoperative fluctuation and evaluate associated factors in vivo.

METHODS

Participants were 18 Chinese patients with uveal melanoma who were elected to IPT. Undiluted aqueous humor samples were collected at Iodine plaque implant and removal time, then stored immediately at -80°C until assayed. The concentration of VEGF-A, PLGF and other 7 cytokines comprising interleukin-2 (IL-2), IL-8, IL-10, interferon (IFN)-γ, programmed death (PD)-1, transforming growth factor (TGF)-β1 and insulin-like growth factor (IGF)-1 in aqueous humor was measured using Raybiotech immunoassay kit, a high throughput strategy. The VEGF-A and PLGF levels were compared across preoperation and postoperation subgroups, as well as those of other 7 interleukins. Correlation and grouped analyses were conducted to determine the independent effects of clinical parameters and other cytokines on VEGF-A and PLGF concentration or fluctuation. This study set a self-control design.

RESULTS

VEGF-A (P=0.038) and PLGF (P=0.026) were the only two increased cytokines after IPT. Preoperative and postoperative level of VEGF-A and PLGF (r=0.575, P=0.013; r=0.987, P<0.001) correlated with each other significantly. Level of VEGF-A (r=0.626, P=0.005; r=0.588, P=0.01) and PLGF (r=0.616, P=0.007; r=0.588, P=0.01) had positive correlation with tumor thickness consistently. Elevated VEGF-A or PLGF level were strong predictive factors of each other (P=0.007, OR=60.0). The elevated VEGF-A group showed a higher postoperative level of IFN-γ (P=0.005), IL-2 (P<0.001) and IL-10 (P=0.004) in aqueous humor. When the elevated PLGF group got similar results that a higher postoperative level of IFN-γ (P=0.007), IL-2 (P<0.001) and IL-10 (P=0.013) in aqueous humor.

CONCLUSION

This study reveals that VEGF-A and PLGF in aqueous humor significantly increased with tumor thickness and radiation process in uveal melanoma patients. VEGF-A and PLGF may be crucial in uveal melanoma genesis and radiotherapy reactions. Immune mediators comprised IFN-γ, IL-2 and IL-10 could play roles in the link between inflammation and angiogenesis in uveal melanoma when exposed to radiotherapy.

Impact of radiotherapy on immunological parameters, levels of inflammatory factors, and clinical prognosis in patients with esophageal cancer

The aim of this study was to observe dynamic changes in immunological parameters and levels of inflammatory factors from pre-radiotherapy to post-radiotherapy in patients with esophageal cancer, and to evaluate the related clinical prognosis. In all, 110 patients with esophageal cancer who underwent radiotherapy were enrolled. Before radiotherapy, post-radiotherapy, and 3 months after radiotherapy, the percentages of T lymphocyte subsets and natural killer (NK) cells in peripheral blood were detected using flow cytometry. The levels of serum inflammatory factors were measured with the enzyme-linked immunosorbent assay (ELISA). Thirty peripheral blood samples from healthy people were similarly analysed as the control. Before radiotherapy, the percentages of CD4+ and CD8+ T cells and NK cells, and the CD4+/CD8+ rate in esophageal cancer patients were significantly different from those in the healthy control group (P < 0.001); the levels of inflammatory factors were increased significantly (P < 0.001). The percentages of the above cells and the levels of inflammatory factors also differed statistically significantly between pre- and post-radiotherapy (P < 0.001) in the esophageal cancer patients. Three months after radiotherapy, the percentages of CD3+ (P = 0.453), CD4+ (P = 0.108), and CD8+ T cells (P = 0.163) and NK cells (P = 0.103) had recovered to the level before radiotherapy; and the levels of TNF-α (P = 0.101), IL-6 (P = 0.302) and IL-8 (P = 0.250) were also restored. After radiotherapy, alterations in immunological parameters were associated with the irradiation volume and the myelosuppression condition. Patients with recovered immunological parameters showed a longer median survival time than those with poor recovery of immunological parameters. For esophageal cancer patients who were immunosuppressive and had an activated inflammatory response before radiotherapy, radiotherapy aggravated these symptoms, and this aggravation was positively associated with myelosuppression and irradiation volume. In addition, recovery of the immunological parameters indicated better prognosis.

Quality evaluation of Panax quinquefolium from different cultivation regions based on their ginsenoside content and radioprotective effects on irradiated mice

Ginsenosides are one of major types of bioactive compounds in American ginseng (AG) and utilized to assess the quality of various AG samples. The contents of ginsenosides showed cultivation region-related variation, which is possibly associated with AG’s pharmacological effect difference. Therefore, to reveal the quality difference of AGs in different cultivation regions, AG samples from seven cultivation regions were evaluated via analyzing their contents of nine ginsenosides and the biochemical parameters in AG-treated irradiated mice. Pre-administration of AG decoctions could reversely modulate the irradiation-induced changes of antioxidant enzymatic activity, cytokine level and hormone level in irradiated mice, which demonstrated that AG had the radioprotective effects due to its antioxidative, immunomodulatory and anti-inflammatory properties. However, this radioprotection effect varied among different cultivation regions of AGs. Collectively, Beijing and Canada-cultivated AGs had the best radioprotection. Heilongjiang and Jilin-originated AGs had the similar pharmacological effects while USA, Shandong and Shaanxi-grown AGs had closer pharmacological effects. This biochemical measurements-based PCA and heatmap clustering of AGs from seven cultivation regions was nearly consistent with ginsencoside content- and the previous serum metabolome-based analyses. However, the pearson correlation analysis revealed that only Rb3 and Rd were significantly correlated with some of assayed biochemical parameters in irradiated mice pretreated with different cultivation regions of AG extracts.

Combining Radiotherapy With Anti-angiogenic Therapy and Immunotherapy; A Therapeutic Triad for Cancer?

Radiotherapy has been used for the treatment of cancer for over a century. Throughout this period, the therapeutic benefit of radiotherapy has continuously progressed due to technical developments and increased insight in the biological mechanisms underlying the cellular responses to irradiation. In order to further improve radiotherapy efficacy, there is a mounting interest in combining radiotherapy with other forms of therapy such as anti-angiogenic therapy or immunotherapy. These strategies provide different opportunities and challenges, especially with regard to dose scheduling and timing. Addressing these issues requires insight in the interaction between the different treatment modalities. In the current review, we describe the basic principles of the effects of radiotherapy on tumor vascularization and tumor immunity and vice versa. We discuss the main strategies to combine these treatment modalities and the hurdles that have to be overcome in order to maximize therapeutic effectivity. Finally, we evaluate the outstanding questions and present future prospects of a therapeutic triad for cancer.

Cytokines and radiation-induced pulmonary injuries

Radiation therapy is one of the most common treatment strategies for thorax malignancies. One of the considerable limitations of this therapy is its toxicity to normal tissue. The lung is the major dose-limiting organ for radiotherapy. That is because ionizing radiation produces reactive oxygen species that induce lesions, and not only is tumor tissue damaged, but overwhelming inflammatory lung damage can occur in the alveolar epithelium and capillary endothelium. This damage may result in radiation-induced pneumonitis and/or fibrosis. While describing the lung response to irradiation generally, the main focus of this review is on cytokines and their roles and functions within the individual stages. We discuss the relationship between radiation and cytokines and their direct and indirect effects on the formation and development of radiation injuries. Although this topic has been intensively studied and discussed for years, we still do not completely understand the roles of cytokines. Experimental data on cytokine involvement are fragmented across a large number of experimental studies; hence, the need for this review of the current knowledge. Cytokines are considered not only as molecular factors involved in the signaling network in pathological processes, but also for their diagnostic potential. A concentrated effort has been made to identify the significant immune system proteins showing positive correlation between serum levels and tissue damages. Elucidating the correlations between the extent and nature of radiation-induced pulmonary injuries and the levels of one or more key cytokines that initiate and control those damages may improve the efficacy of radiotherapy in cancer treatment and ultimately the well-being of patients.

T cell abundance in blood predicts acute organ toxicity in chemoradiotherapy for head and neck cancer

Treatment of head and neck squamous cell carcinoma (HNSCC) by chemoradiotherapy (CRT) often results in high-grade acute organ toxicity (HGAOT). As these adverse effects impair the patients' quality of life and the feasibility of the planned therapy, we sought to analyze immunological parameters in tumor material and blood samples obtained from 48 HNSCC patients in order to assess the potential to predict the individual acute organ toxicity. T cells in the tumor stroma were enriched in patients developing HGAOT whereas levels of soluble factors in the plasma and gene expression in whole blood did not coincide with the occurrence of acute organ toxicity. In contrast, the frequency and absolute numbers of selected leukocyte subpopulations measured in samples of peripheral blood mononuclear cells (PBMCs) directly before the beginning of CRT were significantly different in patients with HGAOT as compared to those without. When we validated several potential markers including the abundance of T cells in a small prospective study with 16 HNSCC patients, we were able to correctly predict acute organ toxicity in up to 81% of the patients. We conclude that analysis of PBMCs by fluorescence-activated cell sorting (FACS) might be a convenient strategy to identify patients at risk of developing HGAOT caused by CRT, which might allow to adapt the treatment regimen and possibly improve disease outcome.

Peripheral lymphocyte subset variation predicts prostate cancer carbon ion radiotherapy outcomes

The immune system plays a complementary role in the cytotoxic activity of radiotherapy. Here, we examined changes in immune cell subsets after heavy ion therapy for prostate cancer. The lymphocyte counts were compared with acute radiotherapy-related toxicity, defined according to the Common Terminology Criteria for Adverse Events, and short-term local efficacy, defined based on prostate-specific antigen concentrations. Confirmed prostate cancer patients who had not received previous radiotherapy were administered carbon ion radiotherapy (CIR) in daily fractions of 2.74 GyE with a total dose of 63-66 GyE. Lymphocyte subset counts were investigated before, during and after radiotherapy, and at a 1 month follow-up. Most notable among our findings, the CD4/CD8 ratio and CD19+ cell counts were consistently higher in patients with a complete response (CR) or partial response (PR) to CIR than in those classified in the stable disease (SD) group (P<0.05 for both). But CD3+ and CD8+ cell counts were lower in the CR and PR groups than in the SD group. These results indicate that variations in peripheral lymphocyte subpopulations are predictive of outcome after CIR for prostate cancer.

Review of hematological indices of cancer patients receiving combined chemotherapy & radiotherapy or receiving radiotherapy alone

We observed the outcomes of chemotherapy with radiotherapy (CR) or radiotherapy (RT) alone for cancer patients of larynx, breast, blood and brain origins through complete blood count (CBC). Following were more depressed in CR patients: mean corpuscular hemoglobin-MCH & lymphocytes-LYM, hematocrit, mean corpuscular hemoglobin concentration-MCHC, hemoglobin-HB and red blood cells-RBC. In RT patients, following were more depressed: LYM, MCH and MCHC. Overall, in all cancer patients, the lymphocytes were depressed 52%. There existed a significant difference between white blood cells and RBC in both CR and RT patients. A significant moderate negative correlation is found in HB with the dose range 30-78 (Gray) given to the CR cancer patients. More number of CBC parameters affected in patients treated with CR and RT; but in less percentage as compared to patients who treated with RT alone. The cancer patients suffered from anemia along with immune modulations from the treatments.

Mutations of the human interferon alpha-2b (hIFNα-2b) gene in cancer patients receiving radiotherapy

This research aimed to find out the impact of ionizing radiations on the hIFNα-2b gene of radiotherapy treated cancer patients. The gene hIFNα-2b synthesizes a protein which is an important anticancerous and antiviral protein. The cancer patients (breast, lung, thyroid, oral and prostate) who were undergoing a radiotherapy treatment were selected. A molecular analysis was performed for DNA isolation and gene amplification through PCR, to identify gene mutations. Further, by bioinformatics tools we concluded that how mutations identified in gene sequences have led to the alterations in the hINFα-2b protein in radiotherapy receiving cancer patients. The 32% mutations in the hINFα-2b gene were identified and all were frameshift mutations. Radiotherapy can impact the immune system and cancer patients may modulate their immunity. Understaning the mechanisms of radiotherapy-elicited immune response may be helpful in the development of those therapeutic interventions that can enhance the efficacy of radiotherapy.

miR-15b/16-2 regulates factors that promote p53 phosphorylation and augments the DNA damage response following radiation in the lung

MicroRNAs (miRNAs) are regulatory RNAs frequently dysregulated in disease and following cellular stress. Investigators have described changes in miR-15b expression following exposure to several stress-inducing anticancer agents, including ionizing radiation (IR), etoposide, and hydrogen peroxide. However, the role for miR-15b as a mediator of cellular injury in organs such as the lung has yet to be explored. In this study, we examined miR-15b expression patterns as well as its potential role in DNA damage and repair in the setting of IR exposure. We showed that miR-15b is up-regulated in a dose- and time-dependent manner in human bronchial epithelial cells following IR. miR-15b expression was highest after 2 h of IR and decreased gradually. Survival rates following IR were also higher in miR-15b/16-2-overexpressing cells. Cell cycle arrest in G2/M phase and an increased DNA repair response were observed in IR-exposed miR-15b/16-2 stable cells. We observed an up-regulation of components of the ataxia telangiectasia mutated (ATM)/Chek1/p53 pathway in miR-15b/16-2-overexpressing cells after IR. Moreover, a pathway-based PCR expression array of genes demonstrated that miR-15b/16-2 overexpression significantly induced the expression of genes involved in ATM/ataxia telangiectasia and Rad-3-related (ATR) signaling, apoptosis, the cell cycle, and DNA repair pathways. Here we demonstrated a novel biological link between miR-15b and DNA damage and cellular protection in lung cells. We identified Wip1 (PPM1D) as a functional target for miR-15b and determined that miR-15b induction of the DNA damage response is partially dependent upon suppression of Wip1. Our study suggests that miR-15b/Wip1 could be a potential therapeutic target in radiation-induced lung disease.