Persistent Fatigue in Patients With Hepatocellular Carcinoma Receiving Radiotherapy.

BACKGROUND: Radiation therapy has attracted much attention in the treatment of patients with hepatocellular carcinoma (HCC). However, the association between radiotherapy-related fatigue and HCC has been examined in only a few studies. PURPOSE: This study was designed to explore the change over time in fatigue in patients with HCC treated with radiotherapy and related factors. METHODS: One hundred patients were enrolled in this prospective longitudinal study using convenience sampling at a medical center in northern Taiwan. The Functional Assessment of Chronic Illness Therapy-Fatigue scale, the Brief Pain Inventory-Short Form, and the psychological subscale of Memorial Symptom Assessment Scale-Short Form were used to assess the symptoms at five time points: before radiotherapy (T0), during treatment (T1), and at 1 month (T2), 3 months (T3), and 6 months (T4) after radiotherapy. The generalized estimating equations method was used to determine the changes in fatigue and the influencing factors. RESULTS: Fatigue levels at T1, T2, T3, and T4 were significantly higher than that at T0. Higher fatigue was significantly associated with lower income and poorer functional status. Having worse pain levels and psychological symptoms were both associated with higher fatigue. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: The results indicate fatigue does not recover to the baseline (pretherapy) level by 6 months after radiotherapy. Thus, fatigue in patients with HCC receiving radiotherapy should be regularly and effectively assessed, and patients experiencing pain and psychological symptoms should be given greater attention from clinicians.

Clinical and Dosimetric Results of Proton or Photon Radiation Therapy for Large (>5 cm) Hepatocellular Carcinoma: A Retrospective Analysis.

PURPOSE: Our purpose was to report the clinical and dosimetric attributes of patients with large unresectable hepatocellular carcinoma (HCC) undergoing proton or photon radiation therapy. METHODS AND MATERIALS: We retrospectively analyzed the outcomes and dosimetric indices of 159 patients with >5 cm nonmetastatic HCC who underwent definitive radiation therapy using either protons (N = 105) or photons (N = 54) between 2014 and 2018. Additional photon plans were performed in the 105 proton-treated patients using the same dose prescription criteria for intragroup dosimetric comparison. RESULTS: After a median follow-up of 47 months, patients with biologically effective dose (BED10) ≥ 75 Gy exhibited significantly better local control (LC; 2-year: 85.6% vs 20.5%; P < .001), progression-free survival (PFS; median, 7.4 vs 3.2 months; P < .001), and overall survival (OS; median, 18.1 vs 7.3 months; P < .001) compared with those with BED10 < 75 Gy. Notably, proton-treated patients had a significantly higher BED10 (96 vs 67 Gy; P < .001) and improved LC (2-year: 88.5% vs 33.8%; P < .001), PFS (median, 7.4 vs 3.3 months; P = .001), and OS (median, 18.9 vs 8.3 months; P < .001) than those undergoing photon radiation therapy. Furthermore, patients treated with protons had significantly lower V1 of the liver (P < .001), mean upper gastrointestinal tract dose (P < .001), and mean splenic dose (P < .001), with significantly decreased incidences of radiation-induced liver disease (P = .007), grade ≥3 upper gastrointestinal bleeding (P = .001), and grade ≥3 lymphopenia (P = .003). On multivariate analysis, proton radiation therapy consistently correlated with superior LC (P < .001), PFS (P < .001), and OS (P < .001). In intragroup dosimetric comparison, photon plans demonstrated significantly higher mean liver dose (P < .001) compared with actually delivered proton treatments, and 72 (69%) of them had mean liver dose exceeding 28 Gy, which necessitated target dose de-escalation. CONCLUSIONS: In the context of large HCC radiation therapy, a higher target BED10 was associated with improved outcomes. Notably, proton therapy has demonstrated the capability to deliver ablative doses while also being accompanied by fewer instances of severe toxicity.

Local Interleukin-12 Treatment Enhances the Efficacy of Radiation Therapy by Overcoming Radiation-Induced Immune Suppression.

Radiation therapy (RT) recruits myeloid cells, leading to an immunosuppressive microenvironment that impedes its efficacy against tumors. Combination of immunotherapy with RT is a potential approach to reversing the immunosuppressive condition and enhancing tumor control after RT. This study aimed to assess the effects of local interleukin-12 (IL-12) therapy on improving the efficacy of RT in a murine prostate cancer model. Combined treatment effectively shrunk the radioresistant tumors by inducing a T helper-1 immune response and influx of CD8+ T cells. It also delayed the radiation-induced vascular damage accompanied by increased α-smooth muscle actin-positive pericyte coverage and blood perfusion. Moreover, RT significantly reduced the IL-12-induced levels of alanine aminotransferase in blood. However, it did not further improve the IL-12-induced anti-tumor effect on distant tumors. Upregulated expression of T-cell exhaustion-associated genes was found in tumors treated with IL-12 only and combined treatment, suggesting that T-cell exhaustion is potentially correlated with tumor relapse in combined treatment. In conclusion, this study illustrated that combination of radiation and local IL-12 therapy enhanced the host immune response and promoted vascular maturation and function. Furthermore, combination treatment was associated with less systemic toxicity than IL-12 alone, providing a potential option for tumor therapy in clinical settings.

Radiation-Induced Metabolic Shifts in the Hepatic Parenchyma: Findings from 18F-FDG PET Imaging and Tissue NMR Metabolomics in a Mouse Model for Hepatocellular Carcinoma.

PURPOSE: By taking advantage of 18F-FDG PET imaging and tissue nuclear magnetic resonance (NMR) metabolomics, we examined the dynamic metabolic alterations induced by liver irradiation in a mouse model for hepatocellular carcinoma (HCC). METHODS: After orthotopic implantation with the mouse liver cancer BNL cells in the right hepatic lobe, animals were divided into two experimental groups. The first received irradiation (RT) at 15 Gy, while the second (no-RT) did not. Intergroup comparisons over time were performed, in terms of 18F-FDG PET findings, NMR metabolomics results, and the expression of genes involved in inflammation and glucose metabolism. RESULTS: As of day one post-irradiation, mice in the RT group showed an increased 18F-FDG uptake in the right liver parenchyma compared with the no-RT group. However, the difference reached statistical significance only on the third post-irradiation day. NMR metabolomics revealed that glucose concentrations peaked on day one post-irradiation both, in the right and left lobes-the latter reflecting a bystander effect. Increased pyruvate and glutamate levels were also evident in the right liver on the third post-irradiation day. The expression levels of the glucose-6-phosphatase (G6PC) and fructose-1, 6-bisphosphatase 1 (FBP1) genes were down-regulated on the first and third post-irradiation days, respectively. Therefore, liver irradiation was associated with a metabolic shift from an impaired gluconeogenesis to an enhanced glycolysis from the first to the third post-irradiation day. CONCLUSION: Radiation-induced metabolic alterations in the liver parenchyma occur as early as the first post-irradiation day and show dynamic changes over time.

Ablative Radiotherapy Reprograms the Tumor Microenvironment of a Pancreatic Tumor in Favoring the Immune Checkpoint Blockade Therapy.

The low overall survival rate of patients with pancreatic cancer has driven research to seek a new therapeutic protocol. Radiotherapy (RT) is frequently an option in the neoadjuvant or palliative settings for pancreatic cancer treatment. This study explored the effect of RT protocols on the tumor microenvironment (TME) and their consequent impact on anti-programmed cell death ligand-1 (PD-L1) therapy. Using a murine orthotopic pancreatic tumor model, UN-KC-6141, RT-disturbed TME was examined by immunohistochemical staining. The results showed that ablative RT is more effective than fractionated RT at recruiting T cells. On the other hand, fractionated RT induces more myeloid-derived suppressor cell infiltration than ablative RT. The RT-disturbed TME presents a higher perfusion rate per vessel. The increase in vessel perfusion is associated with a higher amount of anti-PD-L1 antibody being delivered to the tumor. Animal survival is increased by anti-PD-L1 therapy after ablative RT, with 67% of treated animals surviving more than 30 days after tumor inoculation compared to a median survival time of 16.5 days for the control group. Splenocytes isolated from surviving animals were specifically cytotoxic for UN-KC-6141 cells. We conclude that the ablative RT-induced TME is more suited than conventional RT-induced TME to combination therapy with immune checkpoint blockade.

MOSFET dose measurements for proton SOBP beam.

PURPOSE: The aim of this work was to develop a computational scheme for the correction of the LET dependence on the MOSFET response in water phantom dose measurements for a spread-out Bragg peak (SOBP) proton beam. METHODS: The LET dependence of MOSFET was attributed to the stopping power ratio of SiO2 to H2O and to the fractional hole yield in the SiO2 layer. Using literature values for the stopping powers of the continuous slowing down approximation and measured fractional hole yields vs. electric field and LET, formulas were derived for the computation of a dose-weighted correction factor of a SOBP beam. RESULTS: Dose-weighted correction factors were computed for a clinical 190-MeV proton SOBP beam in a high-density polyethylene phantom. By applying correction factors to the SOBP beam, which consisted of weighted monoenergetic Bragg peaks, the MOSFET outputs were predicted and agreed well with the measured MOSFET responses. CONCLUSION: By applying LET dependent correction factors to MOSFET data, quality assurance of dose verification based on MOSFET measurements becomes possible for proton therapy.

Role of Myeloid-Derived Suppressor Cells in High-Dose-Irradiated TRAMP-C1 Tumors: A Therapeutic Target and an Index for Assessing Tumor Microenvironment.

PURPOSE: To investigate the temporal and spatial infiltration of TRAMP-C1 tumors by myeloid-derived suppressor cells (MDSCs) after high-dose radiation therapy (RT), and to explore their effect on tumor growth. METHODS AND MATERIALS: TRAMP-C1 intramuscularly tumors were irradiated with a single dose of 8 Gy or 25 Gy. The dynamics of infiltrated MDSCs and their intratumoral spatial distribution were assessed by immunohistochemistry and flow cytometry. Cytokine levels in the blood and tumor were analyzed by multiplex immunoassay. Mice were injected with anti-Gr-1 antibody to determine whether MDSCs affect tumor growth after RT. RESULTS: CD11b+Gr-1+ MDSCs infiltrated TRAMP-C1 tumors irradiated with 25 Gy, but not 8 Gy, within 4 hours and recruitment persisted for at least 2 weeks. Both CD11b+Ly6G+Ly6C+ polymorphonuclear-MDSCs (PMN-MDSCs) and CD11b+Ly6G-Ly6Chi monocytic-MDSCs (M-MDSCs) were involved. Tumor RT also increased the representation of both MDSC subpopulations in the spleen and peripheral blood. Levels of multiple cytokines were increased in the tumors at 2 weeks, including GM-CSF, G-CSF, CCL-3, CCL-5, CXCL-5, IL-6, IL-17α, and VEGF-a; while G-CSF, IL-6, and TNF-α levels increased in the blood. PMN-MDSCs aggregated in the central necrotic region of the irradiated tumors over time, where they were associated with avascular hypoxia (CD31-PIMO+). MDSCs expressed the proangiogenic factor, matrix metalloproteinase-9, and, within the necrotic area, high levels of arginase-1 and indoleamine 2,3-dioxygenase. Depletion of PMN-MDSCs by Gr-1 antibody increased the efficacy of high-dose RT. CONCLUSIONS: PMN-MDSCs infiltrate TRAMP-C1 tumors after high-dose RT. Their spatial distribution suggests they are involved in the evolution of an intratumoral state of necrosis associated with avascular hypoxia, and their phenotype is consistent with them being immunosuppressive. They appear to promote tumor growth after RT, making them a prime therapeutic target for therapeutic intervention. Assessment of MDSCs and cytokine levels in blood could be an index of the need for such an intervention.

Comparison between 68Ga-PSMA-11 PET/CT and multiparametric magnetic resonance imaging in patients with biochemically recurrent prostate cancer following robot-assisted radical prostatectomy.

BACKGROUND/PURPOSE: We sought to compare the diagnostic performances of 68Ga-PSMA-11 PET/CT and prostate/whole-abdomen multiparametric magnetic resonance imaging (PWAmpMRI) in Taiwanese patients with biochemically recurrent prostate cancer following robot-assisted radical prostatectomy. METHODS: Between June 2017 and December 2018, we prospectively enrolled 34 patients. Upon review of all available clinical and imaging data, a best valuable comparator (BVC) was defined on an individual basis in the light of a consensus reached by a multidisciplinary tumor board. Diagnostic positivity was investigated in relation to the different lesion types. RESULTS: On a patient-based analysis, 68Ga-PSMA-11 PET/CT and PWAmpMRI showed a moderate agreement (kappa coefficient = 0.62). 68Ga-PSMA-11 PET/CT identified local recurrences, regional, and non-regional lymph node metastases, and bone metastases in 15, 10, 1, and 5 patients, respectively. Conversely, PWAmpMRI detected these lesions in 26, 8, 1, and 4 patients, respectively. When the BVC was used as reference standard, the positive diagnostic rates for local recurrences, regional lymph node metastases, non-regional lymph node metastases, and bone metastases were 57.7%, 90.9%, 100%, and 100%, respectively for 68Ga-PSMA-11 PET/CT, and 100%, 72.7%, 100%, and 80% for PWAmpMRI, respectively. The use of both PWAmpMRI and 68Ga-PSMA-11 PET/CT showed a complete diagnostic yield for detecting both local recurrence and systemic failure when PSA levels reached 0.5 ng/mL. CONCLUSION: Due to urine radioactivity, 68Ga-PSMA-11 PET/CT performs less than PWAmpMRI on local recurrences. However, it can have a complementary diagnostic role in the detection of lymph node metastases and in identifying non-axial bone metastases beyond the PWAmpMRI scanning field.

Radiation Induces Pulmonary Fibrosis by Promoting the Fibrogenic Differentiation of Alveolar Stem Cells.

The lung is a radiosensitive organ, which imposes limits on the therapeutic dose in thoracic radiotherapy. Irradiated alveolar epithelial cells promote radiation-related pneumonitis and fibrosis. However, the role of lung stem cells (LSCs) in the development of radiation-induced lung injury is still unclear. In this study, we found that both LSCs and LSC-derived type II alveolar epithelial cells (AECII) can repair radiation-induced DNA double-strand breaks, but the irradiated LSCs underwent growth arrest and cell differentiation faster than the irradiated AECII cells. Moreover, radiation drove LSCs to fibrosis as shown with the elevated levels of markers for epithelial-mesenchymal transition and myofibroblast (α-smooth muscle actin (α-SMA)) differentiation in in vitro and ex vivo studies. Increased gene expressions of connective tissue growth factor and α-SMA were found in both irradiated LSCs and alveolar cells, suggesting that radiation could induce the fibrogenic differentiation of LSCs. Irradiated LSCs showed an increase in the expression of surfactant protein C (SP-C), the AECII cell marker, and α-SMA, and irradiated AECII cells expressed SP-C and α-SMA. These results indicated that radiation induced LSCs to differentiate into myofibroblasts and AECII cells; then, AECII cells differentiated further into either myofibroblasts or type I alveolar epithelial cells (AECI). In conclusion, our results revealed that LSCs are sensitive to radiation-induced cell damage and may be involved in radiation-induced lung fibrosis.

DOCK6 promotes chemo- and radioresistance of gastric cancer by modulating WNT/ß-catenin signaling and cancer stem cell traits.

Gastric cancer (GC) is the third leading cause of cancer-related mortality worldwide and prognosis after potentially curative gastrectomy remains poor. Administration of GC-targeting molecules in combination with adjuvant chemo- or radiotherapy following surgical resection has been proposed as a potentially effective treatment option. Here, we have identified DOCK6, a guanine nucleotide exchange factor (GEF) for Rac1 and CDC42, as an independent biomarker for GC prognosis. Clinical findings indicate the positive correlation of higher DOCK6 expression with tumor size, depth of invasion, lymph node metastasis, vascular invasion, and pathological stage. Furthermore, elevated DOCK6 expression was significantly associated with shorter cumulative survival in both univariate and multivariate analyses. Gene ontology analysis of three independent clinical GC cohorts revealed significant involvement of DOCK6-correlated genes in the WNT/ß-catenin signaling pathway. Ectopic expression of DOCK6 promoted GC cancer stem cell (CSC) characteristics and chemo- or radioresistance concomitantly through Rac1 activation. Conversely, depletion of DOCK6 suppressed CSC phenotypes and progression of GC, further demonstrating the pivotal role of DOCK6 in GC progression. Our results demonstrate a novel mechanistic link between DOCK6, Rac1, and ß-catenin in GCCSC for the first time, supporting the utility of DOCK6 as an independent marker of GC.

Sunitinib Treatment-elicited Distinct Tumor Microenvironment Dramatically Compensated the Reduction of Myeloid-derived Suppressor Cells.

BACKGROUND/AIM: The clinical response rate of prostate cancer to tyrosine kinase inhibitor (TKI) monotherapy is low. The mechanisms of resistance to TKI are unclear. This study aimed to examine if the tumor microenvironment (TME) is involved in the resistance. MATERIALS AND METHODS: The anti-vascular effect of Sutent was examined by immunofluorescent staining in TRAMP-C1 tumor. The percentage of CD11b+ population were analyzed by flow cytometry. The level of cytokines and chemokines were measured by multiplex immunoassay. RESULTS: The Sutent monotherapy caused 1.5 days of tumor growth delay, chronic hypoxia, and more mature vasculature. Sutent monotherapy increased the percentage of polymorphonuclear myeloid-derived suppressor cells (MDSCs) in peripheral blood. The evolved TME triggered the re-distribution of myeloid cells in chronically hypoxic areas. The multiplex immunoassay indicated higher levels of several cytokines and chemokines both in tumors and the blood. CONCLUSION: Sunitinib treatment induced a distinct tumor microenvironment that impaired the efficient reduction of MDSCs by TKI.

Multimodal imaging reveals transient liver metabolic disturbance and sinusoidal circulation obstruction after a single administration of ketamine/xylazine mixture.

A ketamine/xylazine (K/X) mixture is widely used before and during experiments in rodents. However, the impact of short-term use of K/X mixture and its influences on data interpretation have rarely been discussed. In this study, we administered one shot of a K/X mixture and examined acute hepatic responses using biochemical analysis, histopathological examination, and non-invasive imaging to determine the delay required prior to further assessment of the liver to avoid confounding effects triggered by anaesthesia. After the K/X injection, aspartate aminotransferase (AST) in serum was significantly elevated from 3 to 48 h. Obstructed sinusoidal circulation lasting for 24 or 36 h was revealed by DCE-MRI and drug distribution analysis, respectively. Metabolic alterations were detected at 3 h by NMR analysis and FDG-PET. Moreover, ultrasonography showed that lipid droplet accumulation increased from 1 to 16 h and declined thereafter. Taken together, our findings show that the K/X mixture induces acute hepatotoxicity and metabolic disturbance, and these disturbances cause hemodynamical disorders in the liver. The required time interval for recovery from K/X impact was dependent on the chosen assay. It took at least 16 h for metabolic recovery and 36 h for recovery of sinusoidal circulation. However, the liver was not fully recovered from the injury within 48 h.

Adverse birth outcomes in adolescent and young adult female cancer survivors: a nationwide population-based study.

BACKGROUND: For female adolescent and young adult (AYA), cancer with treatments may affect their children's health. Our aim was to determine reliable risk estimates of adverse birth outcomes in AYA cancer survivors and the differential effects of treatments. METHODS: The study population of 4547 births in the AYA cancer survivor group and 45,463 in the comparison group were identified from two national databases between 2004 and 2014. Detailed maternal health conditions, such as maternal comorbidities, medication use during pregnancy and lifestyles, were adjusted in the statistical analyses. The outcomes included low birth weight, preterm labour, stillbirth, small or large for gestational age, a 5-min Apgar score <7, congenital malformation and foetal distress. RESULTS: The AYA cancer survivor group had a 9% higher risk of overall adverse birth outcomes (adjusted odds ratio, 1.09; 95% confidence interval, 1.02-1.16), especially low birth weight and preterm labour than the comparison group. The radiotherapy-only group additionally had a higher risk of foetal distress, and a 5-min Apgar score <7. CONCLUSION: AYA cancer survivors, especially those who have received radiotherapy, still have higher risks of adverse birth outcomes after adjusting for detailed maternal health conditions. Preconception counselling and additional surveillance may be warranted in this population.

Clinical Outcomes of Patients With Unresectable Cholangiocarcinoma Treated With Proton Beam Therapy.

OBJECTIVE: To investigate the clinical outcomes and failure patterns of patients with unresectable cholangiocarcinoma (CC) who had been treated with proton beam therapy (PBT). METHODS: The authors retrospectively examined 30 patients with unresectable CC who had undergone PBT between November 2015 and December 2017. Survival curves were plotted with the Kaplan-Meier method. Independent predictors of survival were identified by multivariate Cox proportional hazard regression analyses. Complications were assessed using the Common Terminology Criteria for Adverse Events v4.0. RESULTS: The median tumor size was 7 cm. Seventeen patients (56.7%) had regional lymph node metastases. The median radiation dose was 72.6 cobalt gray equivalents, and 23 patients (76.7%) received concurrent chemotherapy. The 1-year local control, regional control, and distant metastases-free rates were 88%, 86%, and 68%, respectively. The median overall survival and progression-free survival were 19.3 and 10.4 months, respectively. The median jaundice-free survival was 13 months, with a 1-year biliary tract infection (BTI)-free rate of 58%. Patients who received concurrent chemotherapy had a better median progression-free survival (12.1 vs. 4.7 mo). The most common form of acute toxicity from PBT was acute skin reactions which were rarely severe (grade III: 7% of patients). Three and 2 patients had grade III-IV toxicities and radiation-induced liver disease. There were no deaths caused by PBT or concurrent chemotherapy. CONCLUSIONS: PBT is clinically useful in patients with unresectable CC, even in the presence of large tumors or regional nodal metastases. Its use may induce durable symptom relief, without increasing acute or late toxicity.

Deep learning for fully automated tumor segmentation and extraction of magnetic resonance radiomics features in cervical cancer.

OBJECTIVE: To develop and evaluate the performance of U-Net for fully automated localization and segmentation of cervical tumors in magnetic resonance (MR) images and the robustness of extracting apparent diffusion coefficient (ADC) radiomics features. METHODS: This retrospective study involved analysis of MR images from 169 patients with cervical cancer stage IB-IVA captured; among them, diffusion-weighted (DW) images from 144 patients were used for training, and another 25 patients were recruited for testing. A U-Net convolutional network was developed to perform automated tumor segmentation. The manually delineated tumor region was used as the ground truth for comparison. Segmentation performance was assessed for various combinations of input sources for training. ADC radiomics were extracted and assessed using Pearson correlation. The reproducibility of the training was also assessed. RESULTS: Combining b0, b1000, and ADC images as a triple-channel input exhibited the highest learning efficacy in the training phase and had the highest accuracy in the testing dataset, with a dice coefficient of 0.82, sensitivity 0.89, and a positive predicted value 0.92. The first-order ADC radiomics parameters were significantly correlated between the manually contoured and fully automated segmentation methods (p < 0.05). Reproducibility between the first and second training iterations was high for the first-order radiomics parameters (intraclass correlation coefficient = 0.70-0.99). CONCLUSION: U-Net-based deep learning can perform accurate localization and segmentation of cervical cancer in DW MR images. First-order radiomics features extracted from whole tumor volume demonstrate the potential robustness for longitudinal monitoring of tumor responses in broad clinical settings. U-Net-based deep learning can perform accurate localization and segmentation of cervical cancer in DW MR images. KEY POINTS: • U-Net-based deep learning can perform accurate fully automated localization and segmentation of cervical cancer in diffusion-weighted MR images. • Combining b0, b1000, and apparent diffusion coefficient (ADC) images exhibited the highest accuracy in fully automated localization. • First-order radiomics feature extraction from whole tumor volume was robust and could thus potentially be used for longitudinal monitoring of treatment responses.

A Comprehensive Review on Current Advances in Peptide Drug Development and Design.

Protein-protein interactions (PPIs) execute many fundamental cellular functions and have served as prime drug targets over the last two decades. Interfering intracellular PPIs with small molecules has been extremely difficult for larger or flat binding sites, as antibodies cannot cross the cell membrane to reach such target sites. In recent years, peptides smaller size and balance of conformational rigidity and flexibility have made them promising candidates for targeting challenging binding interfaces with satisfactory binding affinity and specificity. Deciphering and characterizing peptide-protein recognition mechanisms is thus central for the invention of peptide-based strategies to interfere with endogenous protein interactions, or improvement of the binding affinity and specificity of existing approaches. Importantly, a variety of computation-aided rational designs for peptide therapeutics have been developed, which aim to deliver comprehensive docking for peptide-protein interaction interfaces. Over 60 peptides have been approved and administrated globally in clinics. Despite this, advances in various docking models are only on the merge of making their contribution to peptide drug development. In this review, we provide (i) a holistic overview of peptide drug development and the fundamental technologies utilized to date, and (ii) an updated review on key developments of computational modeling of peptide-protein interactions (PepPIs) with an aim to assist experimental biologists exploit suitable docking methods to advance peptide interfering strategies against PPIs.

Diffusion-weighted MRI and 18F-FDG PET correlation with immunity in early radiotherapy response in BNL hepatocellular carcinoma mouse model: timeline validation.

PURPOSE: Imaging probes/biomarkers that are correlated with molecular or microenvironmental alterations in tumors have been used not only in diagnosing cancer but also in assessing the efficacy of cancer treatment. We evaluated the early response of hepatocellular carcinoma (HCC) to radiation treatment using T2-weighted magnetic resonance imaging (MRI), diffusion-weighted (DW) MRI, and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). METHODS: Orthotopic HCC tumors were established in the right liver lobe of Balb/c mice. Mice were longitudinally scanned using T2-weighted/DW MRI and 18F-FDG PET 1 day before and on days 1, 3, 6, 9 and 13 after irradiation with 15 Gy to the right liver lobe to determine tumor size, apparent diffusion coefficient (ADC) value, and maximum standardized uptake value. Immunohistochemical (IHC) staining was performed to validate the tumor microenvironment. RESULTS: Irradiation markedly retarded tumor growth in the orthotopic HCC model and led to increaes in ADC values as early as on day 1 after irradiation. Irradiation also resulted in increases in 18F-FDG uptake on day 1 that were sustained until the end of the observation period. IHC staining revealed a decrease in the number of proliferative cells and a continuous macrophage influx into irradiated tumors, which dramatically altered the tumor microenvironment. Lastly, in vitro coculture of HCC cells and macrophages led to interaction between the cells and enhanced the cellular uptake of 18F-FDG. CONCLUSION: ADC values and 18F-FDG uptake measured using DW MRI and 18F-FDG PET serve as potential biomarkers for early assessment of HCC tumor responses to radiation therapy.

Distinct Tumor Microenvironment at Tumor Edge as a Result of Astrocyte Activation Is Associated With Therapeutic Resistance for Brain Tumor.

Tumor vasculatures and hypoxia are critical tumor micro-environmental factors associated with tumor response to the therapy and heterogeneous in both time- and location-dependent manner. Using a murine orthotopic anaplastic astrocytoma model, ALTS1C1, this study showed that brain tumor edge had a very unique microenvironment, having higher microvascular density (MVD) and better vessel function than the tumor core, but on the other hand was also positive for hypoxia markers, such as pimonidazole (PIMO), hypoxia inducible factor-1α (HIF-1α), and carbonic anhydrase IV (CAIX). The hypoxia at tumor edge was transient, named as peripheral hypoxia, and caused by different mechanisms from the chronic hypoxia in tumor core. The correlation of CAIX staining with astrocyte activation marker, glial fibrillary acid protein (GFAP), at the tumor edge indicated the involvement of astrocyte activation on the development of peripheral hypoxia. Peripheral hypoxia was a specific trait of orthotopic brain tumors at tumor edge, regardless of tumor origin. The hypoxic cells were resistant to the therapy, regardless of their location. Surviving cells, particularly those at the hypoxic region of tumor edge, are likely the cause of tumor recurrence after the therapy. New therapeutic platform that targets cells in tumor edge is likely to achieve better treatment outcomes.

Optimal Timing for Postsurgical Adjuvant Therapy in Patients with Gastric Cancer: A Propensity Score Matching Study.

Background: In clinical trials, adjuvant therapy (AT) has been shown to improve the prognosis in patients with gastric adenocarcinoma who undergo curative gastrectomy and adequate lymph node dissection. However, the optimal timing for initiating AT is still unclear. Method: We collected data from 538 patients with stage II-III gastric cancer who underwent curative gastrectomy and AT in two tertiary hospitals from 2006 to 2013. Patients were divided into the early group (≤8 weeks, n=393) and the late group (>8 weeks, n=145), based on the interval between gastrectomy and initiation of AT. Propensity score matching was applied according to baseline characteristics. Results: After 1:1 propensity score matching, an even distribution of characteristics in both groups (143:143) was achieved. The 5-year overall survival (OS) rates were 56.6% and 40.2% in the matched early and late groups, respectively (p=0.062), while the corresponding 5-year recurrence-free survival (RFS) rates were 57.6% and 46.4%, respectively (p=0.028). The time to AT initiation was correlated with RFS and had a positive association with OS. The 5-year distant metastasis-free survival was also significantly better (HR 0.682, 95% CI 0.472-0.985, p=0.040), suggesting an early AT results in a better outcome in patients. Conclusion: We observed that initiation of AT within 8 weeks of curative gastrectomy produces better disease control and may contribute to better overall survival.

Predictors of Radiation-Induced Liver Disease in Eastern and Western Patients With Hepatocellular Carcinoma Undergoing Proton Beam Therapy.

PURPOSE: To identify predictors of radiation-induced liver disease (RILD) in patients with hepatocellular carcinoma (HCC) treated with proton beam therapy (PBT). METHODS: This multicenter study included 136 patients with HCC (eastern, n = 102; western, n = 34) without evidence of intrahepatic tumor progression after PBT. The RILD was defined as ascites with alkaline-phosphatase abnormality, grade ≥3 hepatic toxicity, or Child-Pugh score worsening by ≥2 within 4 months after PBT completion. The proton doses were converted to equivalent doses in 2-GyE fractions. The unirradiated liver volume (ULV) was defined as the absolute liver volume (LV) receiving <1 GyE; the standard liver volume (SLV) was calculated using body surface area. Possible correlations of clinicodosimetric parameters with RILD were examined. RESULTS: The mean pretreatment LV was 85% of SLV, and patients with a history of hepatectomy (P < .001) or hepatitis B virus infection (P = .035) had significantly smaller LV/SLV. Nineteen (14%) patients developed RILD. Multivariate logistic regression analysis identified ULV/SLV (P = .001), gross tumor volume (P = .001), and Child-Pugh classification (P = .002) as independent RILD predictors, and mean liver dose and target-delivered dose were not associated with RILD occurrence. A "volume-response" relationship between ULV/SLV and RILD was consistently observed in both eastern and western cohorts. In Child-Pugh class-A patients whose ULV/SLV were ≥50%, 49.9%-40%, 39.9%-30% and <30%, the RILD incidences were 0%, 6%, 16%, and 39% (P < .001), respectively. For the Child-Pugh class-B group, the RILD incidences in patients with ≥60%, 59.9%-40%, and <40% of ULV/SLV were 0%, 14%, and 83% (P = .006), respectively. CONCLUSIONS: The ULV/SLV, not mean liver dose, independently predicts RILD in patients with HCC undergoing PBT. The relative and absolute contraindications for Child-Pugh class-A patient's ULV/SLV are <50% and <30%, and <60% and <40% for Child-Pugh class-B patients, respectively. Our results indicate that the likelihood of hepatic complications for PBT is dictated by similar metrics as that for surgery.