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Clinical and Experimental Medicine Jun 2024CD8 + T cells exert a critical role in eliminating cancers and chronic infections, and can provide long-term protective immunity. However, under the exposure of... (Review)
Review
CD8 + T cells exert a critical role in eliminating cancers and chronic infections, and can provide long-term protective immunity. However, under the exposure of persistent antigen, CD8 + T cells can differentiate into terminally exhausted CD8 + T cells and lose the ability of immune surveillance and disease clearance. New insights into the molecular mechanisms of T-cell exhaustion suggest that it is a potential way to improve the efficacy of immunotherapy by restoring the function of exhausted CD8 + T cells. Transforming growth factor-β (TGF-β) is an important executor of immune homeostasis and tolerance, inhibiting the expansion and function of many components of the immune system. Recent studies have shown that TGF-β is one of the drivers for the development of exhausted CD8 + T cells. In this review, we summarized the role and mechanisms of TGF-β in the formation of exhausted CD8 + T cells and discussed ways to target those to ultimately enhance the efficacy of immunotherapy.
Topics: Humans; Transforming Growth Factor beta; CD8-Positive T-Lymphocytes; Immunotherapy; Neoplasms; Animals
PubMed: 38884843
DOI: 10.1007/s10238-024-01394-0 -
Physical and Engineering Sciences in... Jun 2024The volumetric reduction rate (VRR) was evaluated with consideration for six degrees-of-freedom (6DoF) patient setup errors based on a mathematical tumor model in...
Assessing tumor volumetric reduction with consideration for setup errors based on mathematical tumor model and microdosimetric kinetic model in single-isocenter VMAT for brain metastases.
The volumetric reduction rate (VRR) was evaluated with consideration for six degrees-of-freedom (6DoF) patient setup errors based on a mathematical tumor model in single-isocenter volumetric modulated arc therapy (SI-VMAT) for brain metastases. Simulated gross tumor volumes (GTV) of 1.0 cm and dose distribution were created (27 Gy/3 fractions). The distance between the GTV center and isocenter (d) was set at 0-10 cm. The GTV was translated within 0-1.0 mm (Trans) and rotated within 0-1.0° (Rot) in the three axis directions using affine transformation. The tumor growth volume was calculated using a multicomponent mathematical model (MCTM), and lethal effects of irradiation and repair from damage during irradiation were calculated by a microdosimetric kinetic model (MKM) for non-small cell lung cancer (NSCLC) A549 and NCI-H460 (H460) cells. The VRRs were calculated 5 days after the end of irradiation using the physical dose to the GTV for varying d and 6DoF setup errors. The tolerance value of VRR, the GTV volume reduction rate, was set at 5%, based on the pre-irradiation GTV volume. With the exception of the only one A549 condition where (Trans, Rot) = (1.0 mm, 1.0°) was repeated for 3 fractions, all conditions met all the tolerance VRR values for A549 and H460 cells with varying d from 0 to 10 cm. Evaluation based on the mathematical tumor model suggested that if the 6DoF setup errors at each irradiation could be kept within 1.0 mm and 1.0°, there would be little effect on tumor volume regardless of the distance from the isocenter in SI-VMAT.
PubMed: 38884671
DOI: 10.1007/s13246-024-01451-8 -
Clinical and Translational Radiation... Jul 2024Aim of the present study is to characterize a deep learning-based auto-segmentation software (DL) for prostate cone beam computed tomography (CBCT) images and to...
PURPOSE
Aim of the present study is to characterize a deep learning-based auto-segmentation software (DL) for prostate cone beam computed tomography (CBCT) images and to evaluate its applicability in clinical adaptive radiation therapy routine.
MATERIALS AND METHODS
Ten patients, who received exclusive radiation therapy with definitive intent on the prostate gland and seminal vesicles, were selected. Femoral heads, bladder, rectum, prostate, and seminal vesicles were retrospectively contoured by four different expert radiation oncologists on patients CBCT, acquired during treatment. Consensus contours (CC) were generated starting from these data and compared with those created by DL with different algorithms, trained on CBCT (DL-CBCT) or computed tomography (DL-CT). Dice similarity coefficient (DSC), centre of mass (COM) shift and volume relative variation (VRV) were chosen as comparison metrics. Since no tolerance limit can be defined, results were also compared with the inter-operator variability (IOV), using the same metrics.
RESULTS
The best agreement between DL and CC was observed for femoral heads (DSC of 0.96 for both DL-CBCT and DL-CT). Performance worsened for low-contrast soft tissue organs: the worst results were found for seminal vesicles (DSC of 0.70 and 0.59 for DL-CBCT and DL-CT, respectively). The analysis shows that it is appropriate to use algorithms trained on the specific imaging modality. Furthermore, the statistical analysis showed that, for almost all considered structures, there is no significant difference between DL-CBCT and human operator in terms of IOV.
CONCLUSIONS
The accuracy of DL-CBCT is in accordance with CC; its use in clinical practice is justified by the comparison with the inter-operator variability.
PubMed: 38884004
DOI: 10.1016/j.ctro.2024.100796 -
Frontiers in Plant Science 2024Plantations located outside the species distribution area represent natural experiments to assess tree tolerance to climate variability. Climate change amplifies...
INTRODUCTION
Plantations located outside the species distribution area represent natural experiments to assess tree tolerance to climate variability. Climate change amplifies warming-related drought stress but also leads to more climate extremes.
METHODS
We studied plantations of the European larch (Larix decidua), a conifer native to central and eastern Europe, in northern Spain. We used climate, drought and tree-ring data from four larch plantations including wet (Valgañón, site V; Santurde, site S), intermediate (Ribavellosa, site R) and dry (Santa Marina, site M) sites. We aimed to benchmark the larch tolerance to climate and drought stress by analysing the relationships between radial growth increment (hereafter growth), climate data (temperature, precipitation, radiation) and a drought index.
RESULTS
Basal area increment (BAI) was the lowest in the driest site M (5.2 cm2 yr-1; period 1988-2022), followed by site R (7.5 cm2 yr-1), with the youngest and oldest and trees being planted in M (35 years) and R (150 years) sites. BAI peaked in the wettest sites (V; 10.4 cm2 yr-1; S, 10.8 cm2 yr-1). We detected a sharp BAI reduction (30% of the regional mean) in 2001 when springto-summer conditions were very dry. In the wettest V and S sites, larch growth positively responded to current March and June-July radiation, but negatively to March precipitation. In the R site, high April precipitation enhanced growth. In the driest M site, warm conditions in the late prior winter and current spring improved growth, but warm-sunny conditions in July and dry-sunny conditions in August reduced it. Larch growth positively responded to spring-summer wet conditions considering short (1-6 months) and long (9-24 months) time scales in dry (site M) and wet-intermediate (sites S and R) sites, respectively.
DISCUSSION
Larch growth is vulnerable to drought stress in dry slow-growing plantations, but also to extreme spring wet-cloudy events followed by dry-hot conditions in wet fast-growing plantations.
PubMed: 38882570
DOI: 10.3389/fpls.2024.1404347 -
The Journal of Heredity Jun 2024Strong gene flow from outcrossing relatives tends to blur species boundaries, while divergent ecological selection can counteract gene flow. To better understand how...
Strong gene flow from outcrossing relatives tends to blur species boundaries, while divergent ecological selection can counteract gene flow. To better understand how these two forces affect the maintenance of species boundaries, we focused on a species complex including a rare species, maple-leaf oak (Quercus acerifolia), which is found in only four disjunct ridges in Arkansas. Its limited range and geographic proximity to co-occurring close relatives create the possibility for genetic swamping. In this study, we gathered genome-wide SNPs using restriction-site associated DNA sequencing (RADseq) from 190 samples of Q. acerifolia and three of its close relatives, Q. shumardii, Q. buckleyi, and Q. rubra. We found that Q. shumardii and Q. acerifolia are reciprocally monophyletic with low support, suggesting incomplete lineage sorting, introgression between Q. shumardii and Q. acerifolia, or both. Analyses that model allele distributions demonstrate that admixture contributes strongly to this pattern. Populations of Q. acerifolia experience gene flow from Q. shumardii and Q. rubra, but we found evidence that divergent selection is likely maintaining species boundaries: 1) ex situ collections of Q. acerifolia have a higher proportion of hybrids compared to the mature trees of the wild populations, suggesting ecological selection against hybrids at the seed/seedling stage; 2) ecological traits co-vary with genomic composition; and 3) Q. acerifolia shows genetic differentiation at loci hypothesized to influence tolerance of radiation, drought, and high temperature. Our findings strongly suggest that in maple-leaf oak, selection results in higher divergence at regions of the genome despite gene flow from close relatives.
PubMed: 38881254
DOI: 10.1093/jhered/esae033 -
Seminars in Radiation Oncology Jul 2024Treating radioresistant and bulky tumors is challenging due to their inherent resistance to standard therapies and their large size. GRID and lattice spatially... (Review)
Review
Treating radioresistant and bulky tumors is challenging due to their inherent resistance to standard therapies and their large size. GRID and lattice spatially fractionated radiation therapy (simply referred to GRID RT and LRT) offer promising techniques to tackle these issues. Both approaches deliver radiation in a grid-like or lattice pattern, creating high-dose peaks surrounded by low-dose valleys. This pattern enables the destruction of significant portions of the tumor while sparing healthy tissue. GRID RT uses a 2-dimensional pattern of high-dose peaks (15-20 Gy), while LRT delivers a three-dimensional array of high-dose vertices (10-20 Gy) spaced 2-5 cm apart. These techniques are beneficial for treating a variety of cancers, including soft tissue sarcomas, osteosarcomas, renal cell carcinoma, melanoma, gastrointestinal stromal tumors (GISTs), pancreatic cancer, glioblastoma, and hepatocellular carcinoma. The specific grid and lattice patterns must be carefully tailored for each cancer type to maximize the peak-to-valley dose ratio while protecting critical organs and minimizing collateral damage. For gynecologic cancers, the treatment plan should align with the international consensus guidelines, incorporating concurrent chemotherapy for optimal outcomes. Despite the challenges of precise dosimetry and patient selection, GRID RT and LRT can be cost-effective using existing radiation equipment, including particle therapy systems, to deliver targeted high-dose radiation peaks. This phased approach of partial high-dose induction radiation therapy with standard fractionated radiation therapy maximizes immune modulation and tumor control while reducing toxicity. Comprehensive treatment plans using these advanced techniques offer a valuable framework for radiation oncologists, ensuring safe and effective delivery of therapy for radioresistant and bulky tumors. Further clinical trials data and standardized guidelines will refine these strategies, helping expand access to innovative cancer treatments.
Topics: Humans; Neoplasms; Dose Fractionation, Radiation; Radiation Tolerance; Radiotherapy Planning, Computer-Assisted
PubMed: 38880540
DOI: 10.1016/j.semradonc.2024.05.002 -
Seminars in Radiation Oncology Jul 2024Radiotherapy elicits dose- and lineage-dependent effects on immune cell survival, migration, activation, and proliferation in targeted tumor microenvironments. Radiation... (Review)
Review
Radiotherapy elicits dose- and lineage-dependent effects on immune cell survival, migration, activation, and proliferation in targeted tumor microenvironments. Radiation also stimulates phenotypic changes that modulate the immune susceptibility of tumor cells. This has raised interest in using radiotherapy to promote greater response to immunotherapies. To clarify the potential of such combinations, it is critical to understand how best to administer radiation therapy to achieve activation of desired immunologic mechanisms. In considering the multifaceted process of priming and propagating anti-tumor immune response, radiation dose heterogeneity emerges as a potential means for simultaneously engaging diverse dose-dependent effects in a single tumor environment. Recent work in spatially fractionated external beam radiation therapy demonstrates the expansive immune responses achievable when a range of high to low dose radiation is delivered in a tumor. Brachytherapy and radiopharmaceutical therapies deliver inherently heterogeneous distributions of radiation that may contribute to immunogenicity. This review evaluates the interplay of radiation dose and anti-tumor immune response and explores emerging methodological approaches for investigating the effects of heterogeneous dose distribution on immune responses.
Topics: Humans; Tumor Microenvironment; Neoplasms; Radiotherapy Dosage; Immunotherapy; Dose-Response Relationship, Radiation; Animals
PubMed: 38880534
DOI: 10.1016/j.semradonc.2024.04.004 -
International Journal of Radiation... Jun 2024Adjuvant radiotherapy after radical cystectomy in locally advanced bladder cancer was revived after the advancement in precise radiotherapy that decreased the normal...
BACKGROUND
Adjuvant radiotherapy after radical cystectomy in locally advanced bladder cancer was revived after the advancement in precise radiotherapy that decreased the normal pelvic tissue radiation hazards. However, there are still scarce controlled randomized studies addressing this issue.
PATIENTS AND METHODS
One hundred thirty-one cystectomized urothelial bladder cancer patients were enrolled; a hundred and twenty-two were randomized to receive adjuvant radiotherapy (ART) 50 Gy/25 fractions, 4 weeks' post-cystectomy or cystectomy alone (CY). Sixty-two were included in the ART arm and sixty in the CY arm. Twenty-four ART and 30 CY patients received Neoadjuvant chemotherapy. Eleven patients (9%) had cotenant neo-bladder diversion, 6 in ART, and 5 in CY arms. All ART patients were treated with intensity-modulated radiotherapy (IMRT) with daily verification cone-beam CT (CBCT). The median follow-up was 42.7 months.
RESULTS
The 3-year adjusted Locoregional relapse-free survival (LRFS) rate was higher in the ART arm, measuring 81% (95%CI: 69-94) compared to 71% (95% CI: 60-80) (p=0.0457). ART significantly improved the locoregional relapse-free rate in the cystectomy bed and the pelvic side wall (p= 0.016 and 0.001, respectively). The overall survival, event-free, and distant metastasis-free survival did not rank to the level of statistical significance in the 2 arms. Even though the acute side effects were slightly higher in ART, the late toxicities were almost equal in the two groups.
CONCLUSIONS
Adjuvant radiotherapy is safe and quite tolerable after radical cystectomy when using precise radiation techniques. These techniques significantly improved the LRFS but had insignificant improvement on the overall survival. ART did not affect the distant metastasis-free survival. Similar studies are performed in different centers around the world to confirm the value of ART in urothelial bladder cancer.
PubMed: 38879088
DOI: 10.1016/j.ijrobp.2024.05.012 -
International Immunopharmacology Jun 2024This study aimed to investigate the role of JMJD2A in radiotherapy tolerance of esophageal squamous cell carcinoma (ESCC).
OBJECTIVE
This study aimed to investigate the role of JMJD2A in radiotherapy tolerance of esophageal squamous cell carcinoma (ESCC).
METHODS
The levels of H3K9me3 modification were analyzed in anti-PD-1 therapy non-responder or responder patients, and the expression differences of H3K9me3-related modifying enzymes were assessed in TCGA-ESCC and ICGC cohorts. Subsequently, JMJD2A was knocked down in ESCC cells using CRISPR-Cas9 or lentivirus-mediated shRNA, and changes in malignant behavior of ESCC cells were observed. RNA-seq, ATAC-seq, and ChIP-seq analyses were then conducted to investigate the genes and downstream signaling pathways regulated by JMJD2A, and functional validation experiments were performed to analyze the role of downstream regulated genes and pathways in ESCC malignant behavior and immune evasion.
RESULTS
JMJD2A was significantly overexpressed in ESCC and anti-PD-1 therapy non-responders. Knockdown or deletion of JMJD2A significantly promoted the malignant behavior and immune evasion of ESCC. JMJD2A facilitated the structural changes in chromatin and promoted the binding of SMARCA4 to super-enhancers, thereby inducing the expression of GPX4. This resulted in the inhibition of radiation-induced DNA damage and cell ferroptosis, ultimately promoting the malignant behavior and immune evasion of ESCC cells.
CONCLUSION
JMJD2A plays an indispensable role in the malignant behavior and immune evasion of ESCC. It regulates the binding of SMARCA4 to super-enhancers and affects the chromatin's epigenetic landscape, thereby promoting the expression of GPX4 and attenuating iron-mediated cell death caused by radiotherapy. Consequently, it triggers the malignant behavior and immune evasion of ESCC cells.
PubMed: 38878485
DOI: 10.1016/j.intimp.2024.112401 -
Harmful Algae Jun 2024This study aimed to explore the effects of different light intensities on the ecophysiology of eight new Dinophysis isolates comprising four species (D. acuminata, D....
This study aimed to explore the effects of different light intensities on the ecophysiology of eight new Dinophysis isolates comprising four species (D. acuminata, D. ovum, D. fortii, and D. caudata) collected from different geographical regions in the US. After six months of acclimation, the growth rates, photosynthetic efficiency (F/F ratio), toxin content, and net toxin production rates of the Dinophysis strains were examined. The growth rates of D. acuminata and D. ovum isolates were comparable across light intensities, with the exception of one D. acuminata strain (DANY1) that was unable to grow at the lowest light intensity. However, D. fortii and D. caudata strains were photoinhibited and grew at a slower rate at the highest light intensity, indicating a lower degree of adaptability and tolerance to such conditions. Photosynthetic efficiency was similar for all Dinophysis isolates and negatively correlated with exposure to high light intensities. Multiple toxin metrics, including cellular toxin content and net production rates of DSTs and PTXs, were variable among species and even among isolates of the same species in response to light intensity. A pattern was detected, however, whereby the net production rates of PTXs were significantly lower across all Dinophysis isolates when exposed to the lowest light intensity. These findings provide a basis for understanding the effects of light intensity on the eco-physiological characteristics of Dinophysis species in the US and could be employed to develop integrated physical-biological models for species and strains of interest to predict their population dynamics and mitigate their negative effects.
Topics: Photosynthesis; Light; Dinoflagellida; Acclimatization; Marine Toxins; Species Specificity
PubMed: 38876524
DOI: 10.1016/j.hal.2024.102624