Waldeyer ring microbiome in relation to chemoradiation-induced oral mucositis in patients with nasopharyngeal carcinoma.

BACKGROUND: Waldeyer lymphatic ring surrounds the nasopharynx and oropharynx, and no study to date has correlated its microbiome with the severity of oral mucositis (OM) in patients with nasopharyngeal carcinoma (NPC) receiving chemoradiotherapy. METHODS: We performed 16S rRNA sequencing to characterize bacterial microbiome in tumor-affected nasopharynx and the surrounding normal oropharynx. We plotted the abundance and diversity of bacterial taxa and their phylogenetic distance and networks to visualize and compare the differences in pretreatment overall bacterial communities between the nasopharynx and oropharynx in patients with NPC with varying degrees of chemoradiotherapy-induced OM and quality of life. RESULTS: We found microbial signatures in nasopharynx around NPC were not only dissimilar to those in the surrounding oropharynx but were almost unique to each patient. The genetic distance metrics further showed that different tumor microbiota distributions in the nasopharynx among patients with NPC were well-correlated with OM severity and quality of life during chemoradiotherapy. CONCLUSIONS: At Waldeyer ring, the tumor-associated microbiome risk profiles of the respiratory region of nasopharynx, but not commensal microbiota of the alimentary region of oropharynx, could be noninvasive biomarkers for OM susceptibility and might include drug targets for the prevention of chemoradiation-induced OM in patients with Waldeyer ring-derived NPC.

Differential impacts of initial treatment status on long-term survival in patients with sarcomas treated in a referral center according to histologic type and anatomic site.

OBJECTIVE: The aim of this work was to estimate the magnitude of the differential impacts of initial treatment status relative to the impact of classic clinicopathologic factors on the long-term overall survival (OS) of sarcoma patients in a referral cancer center. METHODS: From the institutional database, we identified 2185 patients who presented to the institutional multidisciplinary team (MDT) prior to (N = 717, 32.8%) or after (N = 1468, 67.2%) initial treatment, with a first diagnosis of sarcoma from January 1999 to December 2018. Descriptive, univariate and multivariate analyses were applied to identify the factors related to OS. By performing propensity score matching of each completely MDT-treated patient to a referral patient with similar characteristics, the differential impacts of the identified risk and prognostic factors on OS in the 2 groups were estimated by the Kaplan‒Meier survival curves, log-rank test and Cox proportional hazard regression; the results were compared using calibrated nomograph models and forest plots. RESULTS: Adjusted for the clinicopathologic factors of patient age, sex, primary site, tumor grade, tumor size, resection margin and histology, hazard ratio-based modeling analysis indicated that the initial treatment status was an independent but intermediate prognostic factor associated with long-term OS. The major impacts of the initial and comprehensive MDT-based management on significant improvement of the 20-year OS of sarcomas were reflected in the subgroup of patients with stromal, undifferentiated pleomorphic, fibromatous, fibroepithelial, or synovial neoplasms and tumors in the breast, gastrointestinal tract, or soft tissues of limb and trunk. CONCLUSIONS: This retrospective study supports early referral of patients with soft tissue masses of unknown identity to a specialized MDT before biopsy and initial resection to reduce the risk of death but highlights an unmet need for a greater understanding of some of the most difficult sarcoma subtypes and subsites and their management.

Clonal dynamics of tumor-infiltrating T-cell receptor beta-chain repertoires in the peripheral blood in response to concurrent chemoradiotherapy for Epstein-Barr virus-associated nasopharyngeal carcinoma.

The nasopharyngeal epithelium is highly susceptible to pathogenic infection. More than 95% of nasopharyngeal carcinomas (NPCs) are Epstein-Barr virus (EBV)-associated epithelial cancers densely infiltrated with EBV-free lymphocytes. It remains unknown whether the immune modulating effects of concurrent chemoradiotherapy (CCRT) on the tumor-infiltrating T-cell priming against EBV, tumor-associated antigens, and/or neoantigens can elicit systemic anti-tumor immunity and decrease recurrence or distant metastasis. Using matched EBV-associated NPCs, nasopharyngeal mucosal tissues, and longitudinal serial peripheral blood samples, we explored the spatiotemporal and quantitative changes in expansion and contraction of intratumoral T-cell clonotypes (ITCs) in peripheral blood samples from before, during, and after CCRT. The pre-treatment nasopharyngeal ITC repertoire contained unique mucosa-resident and commonly system-shared T-cell receptors (TCRs), portraying an individualized tumor-associated and/or metagenomic landscape. We found that the long-term disease-free patients had significantly more robust unique mucosa-resident ITCs that migrated into and expanded in the peripheral blood after CCRT than in the patients with recurrence or distant metastasis (Mann-Whitney U test, p = .0110). However, the system-shared productive ITC TCRs specific to the common viruses, such as EBV, cytomegalovirus, and influenzaA, in all the patients with and without recurrence demonstrated almost no expansion after CCRT. Thus, these findings underline the importance of determining the impact of unique intratumoral immune responses, reflected in the peripheral blood, on disease prognosis after treatment and challenge of mechanistically understanding the common systemic immune evasion of EBV in NPC patients.

The Effects of Neoadjuvant Treatment on the Tumor Microenvironment in Rectal Cancer: Implications for Immune Activation and Therapy Response.

BACKGROUND: Because more than one neoadjuvant treatment is available for advanced rectal cancer, the aim of this study was to compare the differential clinical and pathologic effects of different combinations of chemoradiation regimens, treatment sequencing, and timing to surgery on patient outcomes. PATIENTS AND METHODS: Between January 2015 and October 2018, 126 newly diagnosed patients with rectal cancer with magnetic resonance imaging-based cT3-4 or N+ rectal disease for curative-intent treatment received 1 of 4 neoadjuvant regimens, followed by immediate surgery or delayed surgery. Whole post-neoadjuvant surgical specimens were assessed by 3-dimensional digital whole-tumor microarray imaging and immunostaining in pathology to analyze the global tumor pathologic regression grades, residual tumor distribution patterns, the extent of lymphovascular permeation, lymph node positivity, and the overall density of lymphocyte infiltration in the tumor microenvironment. These factors were further examined to identify possible correlations with clinical outcomes. RESULTS: Among the 4 neoadjuvant treatment groups, including 2 conventional regimens, we found a significant increase of stromal CD3+ and CD8+ immune infiltrates in the postneoadjuvant tumor microenvironment in the 3 groups with delayed surgery after different chemoradiation regimens compared with the group with immediate surgery after a short course of RT alone. Independent of neoadjuvant chemoradiation regimens, the post-induction high-intermediate-low stromal-infiltrating CD8+ T-cell densities corresponded to tumor regression grades, distant metastasis rates, and disease-free survival and were prognostic factors for the further stratification of patients with American Joint Committee on Cancer stage III rectal cancer into different risk groups after surgery. CONCLUSION: The effectiveness of induction strategies on tumor remission and disease recurrence in advanced rectal cancer was significantly correlated with an enhanced cytotoxic immune response in the tumor microenvironment.

Tumor-Infiltrating T Cell Receptor-Beta Repertoires are Linked to the Risk of Late Chemoradiation-Induced Temporal Lobe Necrosis in Locally Advanced Nasopharyngeal Carcinoma.

PURPOSE: Temporal lobe necrosis (TLN), a late complication of nasopharyngeal carcinoma (NPC) after concurrent chemoradiotherapy (CCRT), causes permanent neurologic deficits. We aimed to investigate the risk factors for the development of CCRT-induced TLN in locally advanced NPC patients. METHODS AND MATERIALS: The incidence of CCRT-induced TLN was assessed in consecutive patients with NPC initially staged with T3-4N0-3M0 receiving curative intensity modulated radiation therapy (IMRT) and cisplatin-based chemotherapy with long-term follow-up. The TLN risk was evaluated with radiation dose-volume histograms (a dosimetric risk indicator of organ injury) and the dynamics of blood circulating neutrophil-to-lymphocyte ratios (a clinical indicator of systemic inflammation) by linear and logistic regression models. High-throughput unbiased T cell receptor-beta (TCRbeta) sequencing was performed to correlate the different TCRbeta repertoires of NPC-infiltrating lymphocytes (a biological factor of the immune microenvironment) with TLN incidence. RESULTS: In the era of modern IMRT-based CCRT, radiation doses of up to 74 Gy achieved local control rates of more than 90% in both T3 and T4 diseases but still induced a remarkably higher incidence of TLN in the T4 patients (30.14%) compared with the rare incidence of TLN observed in the T3 patients (2.78%) (P < .0001). We found that in the T4 NPC patients, univariate and multivariate analyses showed the radiation tolerance dose-volume effect was not an absolutely independent factor influencing TLN occurrence. However, increased TLN risk was observed in association with higher pre-CCRT baseline and post-CCRT neutrophil-to-lymphocyte ratios. There was also a link between intratumoral TCRbeta repertoire subtypes and TLN incidence. Combining the inherent TCRbeta genomic susceptibility with the clinical variable neutrophil-to-lymphocyte ratio better predicted the risk of TLN for T4 NPC patients after CCRT. CONCLUSIONS: The associations of tumor-infiltrating lymphocyte repertoires and blood circulating neutrophil-to-lymphocyte ratios with TLN occurrence in T4 NPC patients suggest that the immune and inflammatory milieus play roles in the late brain damage caused by CCRT. Modulated or provoked by CCRT locally and systemically, the reciprocal interactions of neutrophils and lymphocytes in the intracranial NPC-associated immune microenvironment could be a key driver of chronic TLN pathogenesis.

The Role of Promyelocytic Leukemia Protein in Steatosis-Associated Hepatic Tumors Related to Chronic Hepatitis B virus Infection.

The persistence of hepatitis B surface antigen (HBsAg) is a risk factor for the development of steatosis-associated tumors in chronic hepatitis B virus (HBV) infection, yet little is known about the metabolic link with this factor. We correlated HBV-related pathogenesis in genetically engineered mice and human carriers with metabolic proteomics and lipogenic gene expression profiles. The immunohistochemistry showed that the promyelocytic leukemia protein (PML, a tumor suppressor involved in genome maintenance and fatty acid oxidation), being inversely influenced by the dynamic HBsAg levels from acute phase to seroclearance, appeared as a lipo-metabolic switch linking HBsAg-induced steatosis (lipogenesis) to HBsAg-lost fat-burning hepatocarcinogenesis (lipolysis). Knockdown of PML in HBsAg-transgenic mice predisposed to obesity and drove early steatosis-specific liver tumorigenesis. Proteome analysis revealed that the signaling pathways corresponding to energy metabolism and its regulators were frequently altered by suppression or depletion of PML in the HBsAg-transgenic mice, mainly including oxidative phosphorylation and fatty acid metabolism. Expression profiling further identified upregulation of stearoyl-CoA desaturase 1 (Scd1) and epigenetic methylation of NDUFA13 in the mitochondrial respiratory chain and the cell cycle inhibitor CDKN1c in concordance to the increased severity of lipodystrophy and neoplasia in the livers of HBsAg-transgenic mice with PML insufficiency. The defect in lipolysis in PML-deficient HBsAg-transgenic mice made the HBsAg-induced adipose-like liver tumors vulnerable to synthetic lethality from toxic saturated fat accumulation with a Scd1 inhibitor. Our findings provide mechanistic insights into the evolution of steatosis-associated hepatic tumors driven by reciprocal interactions of HBsAg and PML, and a potential utility of lipid metabolic reprogramming as a treatment target.

Spatiotemporal homogeneity and distinctness of the T-cell receptor ß-chain repertoires in Epstein-Barr virus-associated primary and metastatic nasopharyngeal carcinomas.

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated lymphoepithelioma. The aim of this study was to characterize the homogeneity and distinctness of the T-cell repertoires within and between primary and metastatic NPCs. We used ultra-deep sequencing of the hypervariably rearranged antigen-binding CDR3 regions of T-cell receptor beta (TCRbeta ) to comprehensively profile the T-cell repertoires in NPC patients receiving definitive chemoradiotherapy with long-term follow-up. We observed not only various spatially heterogeneous patient-specific TCRbeta clone compositions that changed with time but also several commonly enriched TCRbeta subclones that were constantly shared between primary NPCs in the head and neck regions, locally recurrent tumors after treatment and later-developed distant metastatic tumors in the liver, lung and bone. Comparison of the overlap frequency of the T-cell clonality between TCRbeta repertoires enabled us to calculate the pairwise genetic distance between primary NPCs of different patients and different sites of metastatic or recurrent NPCs. The constructed NPC phylogeny clearly differentiated the low-risk patients without relapse from the high-risk patients with distant metastasis after chemoradiotherapy. In contrast to the rather low frequency of nonsilent somatic mutations in NPC cells, the degrees of similarity and divergence of NPC-infiltrating lymphocyte TCRbeta repertoires among different patients showed prognostication. Moreover, the persistent presence of commonly NPC-shared in-frame TCRbeta CDR3 gene sequences spatiotemporally identified in the NPC-infiltrating lymphocytes within varied EBV-positive NPCs and their metastases suggest the existence of frequently shared epitopes of neoantigens virally or nonvirally displayed on cancer cells, thereby providing opportunities for the development of precisely tumor-targeted immunotherapy for distant metastasis.

Does Prosthesis-Based Breast Reconstruction Affect the Clinical Outcome of Postmastectomy Radiotherapy?

BACKGROUND: In the last 5 decades, there has been significant advancement of breast reconstruction and postmastectomy radiotherapy for breast cancer care. There has been concern that breast reconstruction may adversely affect the efficacy of postmastectomy radiotherapy. This, however, has not been proven by clear clinical evidence. METHODS: By comparing the locoregional recurrence rates and overall survival after postmastectomy radiotherapy between those with and without prosthesis-based breast reconstruction, a retrospective cohort study of the breast cancer patients was done. Multivariable Cox proportional hazards analysis was used to control the confounding factors. RESULTS: From January 1, 1998 to December 31, 2011, 1015 patients receiving postmastectomy radiotherapy were identified. Among them, 111 patients had prosthesis-based breast reconstruction, and the other 904 did not have breast reconstruction. Thirty-four of 904 (3.8%) patients in the nonreconstructed group and 4 of 111 (3.6%) patients in the reconstructed group developed locoregional recurrence. Multivariable survival analysis found no significant difference both in locoregional recurrence-free survival (hazard ratio, 0.852; P = 0.771) and in overall survival (hazard ratio = 1.317; P = 0.246) between the nonreconstructed group and reconstructed group. CONCLUSIONS: Although postmastectomy radiotherapy has been shown to affect the surgical and cosmetic outcomes of breast reconstruction, prosthesis-based breast reconstruction does not seem to have significant adverse impacts on the locoregional recurrence-free survival and overall survival of postmastectomy radiotherapy.

Confounding factors associated with oral mucositis assessment in patients receiving chemoradiotherapy for head and neck cancer.

PURPOSE: The aim of this study was to identify patient-centered, mucositis-associated adverse impact factors and events that might confound physician-assessed oral mucositis (OM) in head and neck cancer (HNC) patients receiving chemoradiotherapy. METHODS: This was a post hoc analysis of a previously conducted randomized trial to determine the efficacy of 5% phenylbutyrate mouthwash in preventing chemoradiotherapy-induced OM. This analysis identified patient-centered symptomatic, observable, and measurable factors that may confound physician scoring of the severity of OM during chemoradiotherapy. Confounding factors were then combined with physician-rated OM scores according to World Health Organization (WHO) and OM Assessment Scale (OMAS) criteria to investigate the therapeutic implications of OM treatment. RESULTS: The original analysis found no significant differences between experimental and placebo groups with respect to the cumulative incidence of physician-recorded severe OM (WHO ≥3 or OMAS ≥2), patient-reported adverse events, and opioid use. However, patients in the experimental arm had relatively lower rates of OM-associated adverse clinical issues including unplanned short radiation breaks, skipping of chemotherapy, nausea/vomiting, late loss of body weight, and early opioid use, all of which could potentially interfere with physician-assessed OM scoring. When WHO OM grade (functional impact and pain), OMAS ulceration size (organic impact), and prolonged radiation treatment time (cancer treatment impact) were combined, there were significantly fewer interruptions of chemoradiotherapy treatment in symptomatic OM patients in the experimental compared to the placebo group. The benefits conferred by reducing the amount of chemoradiotherapy-related, OM-associated adverse impacts in the experimental group were reflected by better 5-year locoregional recurrence-free survival. CONCLUSIONS: This exploratory study raises questions as to whether the severity reflected by physician-rated OM scores is in concordance with OM-induced adverse impacts on HNC patients. Further investigations are warranted to identify patient-related and cancer-associated symptom burdens that may affect tolerance, compliance, and outcome of chemoradiotherapy and confound the evaluation of therapeutic effects on chemoradiotherapy-induced OM.

Dual oncogenic and tumor suppressor roles of the promyelocytic leukemia gene in hepatocarcinogenesis associated with hepatitis B virus surface antigen.

Proteasome-mediated degradation of promyelocytic leukemia tumor suppressor (PML) is upregulated in many viral infections and cancers. We previously showed that PML knockdown promotes early-onset hepatocellular carcinoma (HCC) in hepatitis B virus surface antigen (HBsAg)-transgenic mice. Here we report the effects of PML restoration on late-onset HBsAg-induced HCC. We compared protein expression patterns, genetic mutations and the effects of pharmacologically targeting PML in wild-type, PML-/-, PML+/+HBsAgtg/o and PML-/-HBsAgtg/o mice. PML-/- mice exhibited somatic mutations in DNA repair genes and developed severe steatosis and proliferative disorders, but not HCC. PML-/-HBsAgtg/o mice exhibited early mutations in cancer driver genes and developed hyperplasia, fatty livers and indolent adipose-like HCC. In PML+/+HBsAg-transgenic mice, HBsAg expression declined over time, and HBsAg-associated PML suppression was concomitantly relieved. Nevertheless, these mice accumulated mutations in genes contributing to oxidative stress pathways and developed aggressive late-onset angiogenic trabecular HCC. PML inhibition using non-toxic doses of arsenic trioxide selectively killed long-term HBsAg-affected liver cells in PML+/+HBsAgtg/o mice with falling HBsAg and rising PML levels, but not normal liver cells or early-onset HCC cells in PML-/-HBsAgtg/0 mice. These findings suggest dual roles for PML as a tumor-suppressor lost in early-onset HBsAg-induced hepatocarcinogenesis and as an oncogenic promoter in late-onset HBsAg-related HCC progression.

Patterns of failure after use of (18)F-FDG PET/CT in integration of extended-field chemo-IMRT and 3D-brachytherapy plannings for advanced cervical cancers with extensive lymph node metastases.

BACKGROUND: The study is to evaluate the patterns of failure, toxicities and long-term outcomes of aggressive treatment using (18)F-FDG PET/CT-guided chemoradiation plannings for advanced cervical cancer with extensive nodal extent that has been regarded as a systemic disease. METHODS: We retrospectively reviewed 72 consecutive patients with (18)F-FDG PET/CT-detected widespread pelvic, para-aortic and/or supraclavicular lymph nodes treated with curative-intent PET-guided cisplatin-based extended-field dose-escalating intensity-modulated radiotherapy (IMRT) and adaptive high-dose-rate intracavitary 3D-brachytherapy between 2002 and 2010. The failure sites were specifically localized by comparing recurrences on fusion of post-therapy recurrent (18)F-FDG PET/CT scans to the initial PET-guided radiation plannings for IMRT and brachytherapy. RESULTS: The median follow-up time for the 72 patients was 66 months (range, 3-142 months). The 5-year disease-free survival rate calculated by the Kaplan-Meier method for the patients with extensive N1 disease with the uppermost PET-positive pelvic-only nodes (26 patients), and the patients with M1 disease with the uppermost PET-positive para-aortic (31 patients) or supraclavicular (15 patients) nodes was 78.5 %, and 41.8-50 %, respectively (N1 vs. M1, p = 0.0465). Eight (11.1 %), 18 (25.0 %), and 3 (4.2 %) of the patients developed in-field recurrence, out-of-field and/or distant metastasis, and combined failure, respectively. The 6 (8.3 %) local failures around the uterine cervix were all at the junction between IMRT and brachytherapy in the parametrium. The rate of late grade 3/4 bladder and bowel toxicities was 4.2 and 9.7 %, respectively. When compared to conventional pelvic chemoradiation/2D-brachytherapy during 1990-2001, the adoption of (18)F-FDG PET-guided extended-field dose-escalating chemoradiation plannings in IMRT and 3D-brachytherapy after 2002 appeared to provide higher disease-free and overall survival rates with acceptable toxicities in advanced cervical cancer patients. CONCLUSIONS: For AJCC stage M1 cervical cancer with supraclavicular lymph node metastases, curability can be achieved in the era of PET and chemo-IMRT. However, the main pattern of failure is still out-of-field and/or distant metastasis. In addition to improving systemic treatment, how to optimize and integrate the junctional doses between IMRT and 3D-brachytherapy in PET-guided plannings to further decrease local recurrence warrants investigation.

Dynamics of wound healing signaling as a potential therapeutic target for radiation-induced tissue damage.

We hypothesized the histone deacetylase inhibitor phenylbutyrate (PB) has beneficial effects on radiation-induced injury by modulating the expression of DNA repair and wound healing genes. Hamsters received a radiosurgical dose of radiation (40 Gy) to the cheek and were treated with varying PB dosing regimens. Gross alteration of the irradiated cheeks, eating function, histological changes, and gene expression during the course of wound healing were compared between treatment groups. Pathological analysis showed decreased radiation-induced mucositis, facilitated epithelial cell growth, and preventing ulcerative wound formation, after short-term PB treatment, but not after vehicle or sustained PB. The radiation-induced wound healing gene expression profile exhibited a sequential transition from the inflammatory and DNA repair phases to the tissue remodeling phase in the vehicle group. Sustained PB treatment resulted in a prolonged wound healing gene expression profile and delayed the wound healing process. Short-term PB shortened the duration of inflammatory cytokine expression, triggered repeated pulsed expression of cell cycle and DNA repair-regulating genes, and promoted earlier oscillatory expression of tissue remodeling genes. Distinct gene expression patterns between sustained and short-term treatment suggest dynamic profiling of wound healing gene expression can be an important part of a biological therapeutic strategy to mitigate radiation-related tissue injury.

Promyelocytic leukaemia protein links DNA damage response and repair to hepatitis B virus-related hepatocarcinogenesis.

DNA damage response and repair pathways are important barriers to carcinogenesis. Here, we show that promyelocytic leukaemia (PML, also known as TRIM19), involved in sensing DNA damage and executing homologous recombination repair, is down-regulated in non-tumour liver cells surrounding hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). No PML mutation or deletion was found in HBV-infected liver or HCC cells. Immunohistochemical analysis of liver biopsies from patients with breast or liver cancer and HBV reactivation after chemotherapy revealed PML up-regulation and HBV exacerbation in normal liver tissue in response to DNA damage (functional PML), PML down-regulation in HCC peritumour cells associated with high HBsAg accumulation and low HBV replication activity (suppressive PML), and heterogeneous nuclear PML expression in HCC cells that lost HBV DNA and HBsAg and were non-reactive to DNA damage (dysregulated PML). Loss of PML in HBsAg-transgenic mice promoted chromosome breaks in liver cells and accelerated the accumulation of body and liver fat and the development of a liver steatosis-dysplasia-adenoma-carcinoma sequence in an inflammation-independent and male-predominant manner, compared to PML knock-out or HBsAg-transgenic mice during the same time period. These results indicate that PML deficiency facilitates genomic instability and promotes HBsAg-related hepatocarcinogenesis, which also involves androgen and lipid metabolism. These findings uncover a novel PML link between HBV-related tumourigenesis, DNA repair, and metabolism.

Defective DNA damage response and repair in liver cells expressing hepatitis B virus surface antigen.

Hepatitis B virus (HBV) is implicated in liver cancer. The aim of this study was to find out whether HBV or its components [HBV surface antigen (HBsAg), HBV core protein (HBc), and HBV X protein (HBx)] could interfere with the host DNA damage response and repair pathway. The full HBV genome or individual HBV open-reading frame (ORF) was introduced into HepG2 cells to examine the effect on host genomic stability, DNA repair efficacy in response to double-strand DNA damage, and DNA damage-induced cell death. Responses to apoptosis induction in the HBV ORF-transfected HepG2 cells were also compared with those in HBV-positive and HBV-negative human hepatocellular carcinoma (HCC) cells. In the absence of HBV replication, accumulation of HBsAg in liver cells without other HBV proteins enhanced DNA repair protein and tumor suppressor promyelocytic leukemia (PML) degradation, which resulted in resistance to apoptosis induction and deficient double-strand DNA repair. However, HBsAg-positive cells exhibited increased cell death with exposure to the poly(ADP-ribose) polymerase inhibitor that blocks single-strand DNA repair. These results indicate that suppression of PML by HBsAg disrupts cellular mechanisms that respond to double-strand DNA damage for DNA repair or apoptosis induction, which may facilitate hepatocarcinogenesis and open up a synthetic lethality strategy for HBsAg-positive HCC treatment.

Phenylbutyrate mouthwash mitigates oral mucositis during radiotherapy or chemoradiotherapy in patients with head-and-neck cancer.

PURPOSE: Deleterious oral mucositis (OM) develops during radiotherapy (RT) or chemoradiotherapy for head-and-neck cancer (HNC) patients. There are currently no effective cytoprotective treatments for OM without a potential risk of tumor protection. This randomized, double-blind, placebo-controlled pilot study aimed to determine the therapeutic safety and efficacy of phenylbutyrate (an antitumor histone deacetylase inhibitor and chemical chaperone) 5% mouthwash for treating OM caused by cancer therapy. METHODS AND MATERIALS: Between September 2005 and June 2006, 36 HNC patients were randomized to standard oral care plus 5 mL of either phenylbutyrate 5% mouthwash (n = 17) or placebo (mouthwash vehicle, n = 19) taken four times daily (swish and spit). Treatment began when mild mucositis (Radiation Therapy Oncology Group Grade 1) occurred, and ended 4 weeks after RT completion. Safety and efficacy were based on adverse events, physical examination, laboratory determinations, vital signs, Oral Mucosa Assessment Scale (OMAS) and World Health Organization scores, the ability to eat, body weight change, local control, and survival. RESULTS: We found no severe drug-related side effect. At RT doses of 5500-7500 cGy, phenylbutyrate significantly mitigated the severity of mucositis compared with placebo, based on both the WHO score (severity ≥ 3; p = 0.0262) and the OMAS scale (ulceration score ≥ 2; p = 0.0049). The Kaplan-Meier estimates for 2- and 3-year local control, and overall survival were 100% and 80.8%, and 78.6% and 64.3%, respectively, in the phenylbutyrate group and 74.2% and 74.2%, and 57.4% and 50.2%, respectively, in the placebo group. CONCLUSIONS: This pilot trial suggested that phenylbutyrate mouthwash significantly decreased the impact of OM in HNC patients receiving RT or chemoradiotherapy and did not confront the tumor control. Larger Phase II randomized trials are needed to confirm these results.

Phenylbutyrate suppresses distinct skin reactions that are enhanced by blockade of epidermal growth factor receptor signaling.

BACKGROUND: Epidermal growth factor receptor inhibitors (EGFRIs) cause skin inflammation, and understanding the factors that mediate this reaction is fundamental for designing therapies for EGFRI-related cutaneous side effects. OBJECTIVE: We characterized EGFRI-enhanced skin reactions and evaluated the therapeutic efficacy of phenylbutyrate, a histone deacetylase inhibitor. METHODS: PD168393, an EGFRI, was applied topically to the ear skin of mice with or without mast cell deficiency. The skin was then irritated once or pre-sensitized and repeatedly challenged with 2,4-dinitrofluorobenzene (DNFB). The reaction pattern, the type and number of infiltrating cells, changes in protein, cytokine (TNF-α) and chemokine (CCL2) expression, and the immune response were analyzed. Phenylbutyrate, formulated as a gel for topical treatment or dissolved in water for intraperitoneal administration, was tested as a treatment. RESULTS: EGFRI rapidly upregulated the mast cell chemotactic factor, stem cell factor (SCF) and augmented DNFB-induced immediate contact dermatitis within hours of treatment in the presence of mast cells. Topical phenylbutyrate treatment suppressed EGFRI-induced SCF expression in the epithelium, inhibited DNFB-induced mast cell recruitment in the dermis, and ameliorated the EGFRI-enhanced acute skin reaction. EGFRI also enhanced the delayed-type DNFB-induced hypersensitive reaction that was mast-cell independent but was associated with T lymphocytes. Systemic phenylbutyrate administration suppressed EGFRI-enhanced delayed-type skin hypersensitivity by increasing the number and function of Foxp3(+) T regulatory suppressor cells, which inhibited T helper cell proliferation. CONCLUSIONS: Our data suggest that phenylbutyrate has dual beneficial therapeutic effects on EGFRI-enhanced acute (local inflammatory) and late (systemic immune) skin reactions.

Promyelocytic leukemia nuclear bodies link the DNA damage repair pathway with hepatitis B virus replication: implications for hepatitis B virus exacerbation during chemotherapy and radiotherapy.

The mechanism responsible for hepatitis B virus (HBV) exacerbation during chemotherapy and radiotherapy remains unknown. We investigated whether the activation of DNA repair pathways influences HBV replication. The upregulation of the promyelocytic leukemia (PML) protein and its associated PML nuclear body (PML-NB) by chemotherapy and irradiation-induced DNA repair signaling correlated with the upregulation of HBV pregenomic transcription, HBV-core expression, and HBV DNA replication. The HBV-core protein and HBV DNA localized to PML-NBs, where they associated with PML and histone deacetylase 1 (HDAC1). Chemotherapy and radiotherapy affected the interactions between PML, HBV-core, and HDAC1. The enhanced protein-protein interaction between PML and HBV-core inhibited PML-mediated apoptosis and decreased PML-associated HDAC activity. The reversal of HDAC-mediated repression on the HBV covalently closed circular DNA basal core promoter resulted in the amplification of HBV-core and pregenomic expression. These results suggest that PML in PML-NBs links the DNA damage response with HBV replication and may cooperate with HBV-core and HDAC1 on the HBV covalently closed circular DNA basal core promoter to form a positive feedback loop for HBV exacerbation during chemotherapy and radiotherapy.

Epigenetic therapy using the histone deacetylase inhibitor for increasing therapeutic gain in oral cancer: prevention of radiation-induced oral mucositis and inhibition of chemical-induced oral carcinogenesis.

In addition to genetic changes, epigenetic aberrations also play important roles in radiation- and chemical-induced disorders and carcinogenesis. The present study investigated whether epigenetic therapy with a histone deacetylase (HDAC) inhibitor has dual benefits for radiation-induced oral mucositis and chemical-induced oral carcinogenesis, which should be treated at the same time. The HDAC inhibitor phenylbutyrate was first tested to determine if it influences DNA damage repair and survival in irradiated normal cells in vitro by investigating the patterns and dynamics of phospho-gammaH2AX foci, Rad51 foci and phospho-gammaH2AX/Rad51 colocalization and using the comet and clonogenic assays. Oral mucositis or carcinogenesis was induced in hamsters using radiation or 7,12-dimethylbenz[a]anthracene (DMBA) irritation to the cheek pouch. The ability of phenylbutyrate formed in proper carriers to prevent radiation-induced oral mucositis and inhibit chemical-induced oral carcinogenesis was assessed. The treated or untreated irradiated or DMBA-irritated oral tissues or mucosal epithelia were subjected to the studies of histology, immunohistochemistry, gene expression, comet assay, HDAC activity or oxidative stress. We found that phenylbutyrate promoted DNA repair and survival in normal cells after radiation. Compared with blank or vehicle-treated hamsters, the irradiated mucosa treated with phenylbutyrate had significantly lower oxidative stress and tumor necrosis factor-alpha expression and less severe oral mucositis of a shorter duration. A reduction of the oral tumor incidence, burden and progression by phenylbutyrate correlated with the suppression of oncomiRs and Rad51 overexpression, the upregulation of differentiation markers and the decrease of intracellular HDAC activity and oxidative stress during DMBA-induced oral carcinogenesis. Thus, epigenetic therapy using the HDAC inhibitor as an adjuvant to radiotherapy for chemical-induced oral cancer may provide a promising strategy combining the prevention of radiation-induced oral mucositis and the inhibition of oral carcinogenesis.

Use of combined molecular biomarkers for prediction of clinical outcomes in locally advanced tonsillar cancers treated with chemoradiotherapy alone.

BACKGROUND: Environmental exposures to tobacco, alcohol, human papillomavirus (HPV) and/or Epstein-Barr virus (EBV), all of which can perturb multiple cell cycle proteins or tumor suppressors, have been implicated in the pathogenesis of different subsets of head and neck cancers. The aim of this study was to investigate to which extent the virus infection by itself, and/or the altered cell cycle proteins, contributes to prognosis in locally advanced tonsillar squamous cell carcinomas (TSCCs) treated with concurrent chemoradiotherapy (CCRT) alone. METHODS: Serial tumor tissue arrays from archival samples were tested for the presence of HPV genome integration or EBV episome by means of DNA sequencing, real-time polymerase chain reaction (PCR), and in situ hybridization. Alterations of cell cycle proteins (p53, pRb, and p21) were evaluated by immunohistochemical staining. The association of viral presence with altered cell cycle proteins was correlated to clinical outcomes. RESULTS: Of the 46 patients with the same T2N2bM0 stage IVA among consecutive patients with TSCC, 23 (50%) had integrated HPV DNA and only 1 (2%) had EBV episome. The HPV types detected were almost all HPV-16. A reduced expression pattern of p53, pRb, and p21 was noted in HPV-positive tumors, and the incremental number of alterations in the 3 proteins was significantly associated with HPV-negative tumors. The presence or absence of HPV together with the number of altered expression of the 3 cell cycle markers resulted in further identification of 4 biologically and clinically distinct subgroups with different outcomes after CCRT. CONCLUSIONS: Use of combined biomarkers of oncogenic HPV and tumor suppressors of p53, pRb, and p21 in advanced TSCC provides prognostic molecular classification superior to the TNM stage system and identifies low-risk patients for organ preservation by CCRT alone and high-risk patients who might benefit from planned tonsillectomy and neck dissection before or after CCRT.

Is final TNM staging a predictor for survival in locally advanced rectal cancer after preoperative chemoradiation therapy?

BACKGROUND: Neoadjuvant chemoradiation therapy has improved the local control rate and overall survival in locally advanced rectal cancers. The purpose of this retrospective study is to evaluate the correlation between the final pathologic stage and survival in these patients. METHODS: Patients with biopsy-proven rectal carcinoma, pretreatment staging by magnetic resonance imaging such as T3 or T4 tumors, or node-positive disease were treated with preoperative concomitant 5-fluorouracil-based chemotherapy and radiation, followed by radical surgical resection. Clinical outcome with survival, disease-free survival, recurrence rate, and local recurrence rate were compared with each T and N findings using the American Joint Committee on Cancer Tumor-Node-Metastasis (TNM) staging system. RESULTS: A total of 248 patients were enrolled in this study. Overall survival and disease-free survival at 1, 3, and 5 years were 97.1, 92, and 89.9% and 87.5, 71.1, and 69.5%, respectively. Thirty-six patients (14.5%) had a pathologic complete response after neoadjuvant therapy. The recurrence rate was significantly different between the pathologic complete response group and residual group (5.6 vs 31.1%; P = .002). Five-year disease-free survival was significantly better in the complete response group than the residual tumor group (93 vs 66%; P = .0045). There was no statistical difference in survival or locoregional recurrence rate between these two groups. CONCLUSIONS: Posttreatment pathologic TNM stage is correlated to disease-free survival and tumor recurrence rate in locally advanced rectal cancer after preoperative chemoradiation. Also, pathologic complete response to neoadjuvant treatment has its oncologic benefit in both overall recurrence and disease-free survival.