Inhibition of c-MET reverses radiation-induced malignant potential in pancreatic cancer

As a treatment option for PDAC, radiation therapy induces good local control. However, radiation also reportedly enhances the malignant potential (e.g., invasion and migration ability) in various cancers, thus increasing the risk of distant metastasis. It remains unclear how radiation induces malignant potential, and how such enhanced malignant potential can be suppressed. In the current study, we evaluated the sequential change of c-Met expression in pancreatic cancer cells following irradiation. We found that irradiation transiently induced c-Met expression in vitro. In an in vivo subcutaneous tumor mouse model, irradiation also enhanced downstream phosphorylated Met (p-Met). Furthermore, this enhancement of p-Met protein expression was suppressed by oral administration of the c-Met inhibitor INC280. Irradiated pancreatic cancer cells with enhanced c-Met expression exhibited higher malignant potential, including invasion and migration ability, compared with cells showing low c-Met expression. Pancreatic cancer cells that overexpressed c-met also showed enhanced malignant potential, which was reversed by c-Met inhibition. Additionally, c-Met inhibitor suppressed the metastatic potential in a liver metastasis mouse model using c-met-overexpressing cells. Overall, our present results revealed that irradiation could induce c-met expression in pancreatic cancer cells, leading to enhanced malignant potential (e.g., invasion and migration ability) and thus promoting distant metastasis. Moreover, a c-Met inhibitor could reverse this enhanced malignant potential.

Suppression of beta 2 adrenergic receptor actions prevent UVB mediated cutaneous squamous cell tumorigenesis through inhibition of VEGF-A induced angiogenesis

Although beta 2 adrenergic receptors (β2 ADR) are present in the keratinocytes, their role in cutaneous squamous cell tumorigenesis needs to be ascertained. For the first time, we report here that selective β2 ADR antagonists by inhibiting β2 ADR actions significantly retarded the progression of ultraviolet B (UVB) induced premalignant cutaneous squamous cell lesions. These antagonists acted by inhibiting vascular endothelial growth factor-A (VEGF) mediated angiogenesis to prevent UVB radiation-induced squamous cell carcinoma of the skin.

DNA methylome and transcriptome alterations and cancer prevention by triterpenoid ursolic acid in UVB-induced skin tumor in mice

Nonmelanoma skin cancers (NMSCs) are the most common type of skin cancers. Major risk factors for NMSCs include exposure to ultraviolet (UV) irradiation. Ursolic acid (UA) is a natural triterpenoid enriched in blueberries and herbal medicinal products, and possess anticancer activities. This study focuses on the impact of UA on epigenomic, genomic mechanisms and prevention of UVB-mediated NMSC. CpG methylome and RNA transcriptome alterations of early, promotion and late stages of UA treated on UVB-induced NMSC in SKH-1 hairless mice were conducted using CpG methyl-seq and RNA-seq. Samples were collected at weeks 2, 15, and 25, and integrated bioinformatic analyses were performed to identify key pathways and genes modified by UA against UVB-induced NMSC. Morphologically, UA significantly reduced NMSC tumor volume and tumor number. DNA methylome showed inflammatory pathways IL-8, NF-κB, and Nrf2 pathways were highly involved. Antioxidative stress master regulator Nrf2, cyclin D1, DNA damage, and anti-inflammatory pathways were induced by UA. Nrf2, cyclin D1, TNFrsf1b, and Mybl1 at early (2 weeks) and late (25 weeks) stages were identified and validated by quantitative polymerase chain reaction. In summary, integration of CpG methylome and RNA transcriptome studies show UA alters antioxidative, anti-inflammatory, and anticancer pathways in UVB-induced NMSC carcinogenesis. Particularly, UA appears to drive Nrf2 and its upstream/downstream genes, anti-inflammatory (at early stages) and cell cycle regulatory (both early and late stages) genes, of which might contribute to the overall chemopreventive effects of UVB-induced MNSC. This study may provide potential biomarkers/targets for chemoprevention of early stage of UVB-induced NMSC in human.

Investigation into the use of histone deacetylase inhibitor MS-275 as a topical agent for the prevention and treatment of cutaneous squamous cell carcinoma in an SKH-1 hairless mouse model

Cutaneous squamous cell carcinomas are a common form of highly mutated keratinocyte skin cancers that are of particular concern in immunocompromised patients. Here we report on the efficacy of topically applied MS-275, a clinically used histone deacetylase inhibitor, for the treatment and management of this disease. At 2 mg/kg, MS-275 significantly decreased tumor burden in an SKH-1 hairless mouse model of UVB radiation-induced skin carcinogenesis. MS-275 was cell permeable as a topical formulation and induced histone acetylation changes in mouse tumor tissue. MS-275 was also effective at inhibiting the proliferation of patient derived cutaneous squamous cell carcinoma lines and was particularly potent toward cells isolated from a regional metastasis on an immunocompromised individual. Our findings support the use of alternative routes of administration for histone deacetylase inhibitors in the treatment of high-risk squamous cell carcinoma which may ultimately lead to more precise delivery and reduced systemic toxicity.

A pilot study evaluating chemotherapy tolerability for breast cancer patients who have received prior treatment and chest radiation for Hodgkin Lymphoma

MICROABSTRACT

Women treated with chest radiation for Hodgkin lymphoma (HL) have significantly higher risk of developing breast cancer, and little is known about how these patients tolerate chemotherapy for breast cancer. This small retrospective study identified 15 patients, noting that these patients tolerate proposed chemotherapy regimens for breast cancer in rates similar to those without prior HL and therapeutic radiation.

PURPOSE

Women treated for Hodgkin lymphoma (HL) with chest radiation have significantly higher risk of developing breast cancer, and little is known about how these patients tolerate chemotherapy for breast cancer.

METHODS

Women with breast cancer diagnosed from 1986-2015 after radiation for HL were identified from hospitals and clinics in St. Paul and Minneapolis, Minnesota. Patient, tumor and treatment characteristics, and clinical outcomes were abstracted from medical records and summarized using descriptive statistics. Chemotherapy was defined as tolerated if all scheduled doses and cycles were completed without deviation from the initial plan, with lack of grade 3 or higher toxicity attributable to chemotherapy in categories including blood, cardiac, gastrointestinal, fatigue and pain.

RESULTS

Forty-two patients with breast cancer and prior radiation for HL were identified, 15 of which received chemotherapy for breast cancer. We noted 75% tolerability of taxane-based and 100% tolerability of anthracycline-based chemotherapy, suggesting that most patients with prior radiation for HL tolerate chemotherapy for breast cancer. A subset of patients (N = 7) in this study were also treated with chemotherapy for HL prior to breast cancer diagnosis, and 86% (6 of 7) also tolerated chemotherapy for breast cancer.

CONCLUSIONS

Treatment of breast cancer is strongly influenced by prior treatment of HL. Although this study was small and did not meet statistical significance, the data suggest that these patients tolerate proposed chemotherapy regimens for breast cancer in rates similar to those without prior HL and therapeutic radiation. Larger studies comparing specific chemotherapy dosing schedules are needed to address this complicated population.

Anal Squamous Cell Carcinoma Arising on Radio-Dermatitis Cured with Chemotherapy Alone: Case Report

A squamous cell carcinoma of the anal canal appeared 10 years and 6 months after ionizing radiation therapy (58 Gy) for a previous squamous cell carcinoma in the same region. The patient was treated with chemotherapy alone, which produced a complete remission for 17+ months without relevant acute toxicity.

Two Cases of Secondary Sotf Tissue Sarcomas after Radiotherapy and Radiochemotherapy

Background

The development of secondary soft tissue sarcomas after chemo-radiotherapy is a rare and little known event, but its frequency is increasing.

Patients and Methods

We report two cases of secondary soft tissue sarcomas. The first is the case of a 51-year-old woman treated for Hodgkin's disease with chemotherapy and radiotherapy 15 years before she developed a high-grade malignant pleural sarcoma. The patient had no history of asbestos exposure. The second is the case of a 64-year-old woman with a giant cell malignant histiocytoma secondary to colorectal cancer treated with surgery and radiotherapy nine years before. The patients were not eligible for surgery or radiotherapy. Both were treated with chemotherapy (ifosfamide and epirubicin) without any relevant secondary effects; however, the response to therapy was poor.

Conclusions

The causes of secondary malignancies are multifactorial, but radiation therapy and chemotherapy are certainly implicated in the development of post-therapy neoplasms that are difficult to treat.

[18F-FDG PET/CT contributes to diagnostics and therapy monitoring of radiation-induced angiosarcoma]

Angiosarcomas are rare, aggressive malignant mesenchymal tumours with a poor prognosis. Radiation therapy is an independent risk factor for the development of secondary angiosarcoma. The onset of angiosarcoma may resemble benign lesions, leading to delayed diagnosis. It has been suggested that 18F-fluorodeoxyglucose (FDG) PET/CT scan may be useful in the early diagnosis in differentiating angiosarcoma from benign lesions and in therapy monitoring. We report the utility of 18F-FDG PET/CT scan in the diagnosis and follow-up of radiation-induced angiosarcoma in a patient previously treated for uterine cancer.

Evaluation of the 2-(1-Hexyloxyethyl)-2-devinyl pyropheophorbide (HPPH) mediated photodynamic therapy by macroscopic singlet oxygen modeling

Photodynamic therapy (PDT) is known as a non-invasive treatment modality that is based on photochemical reactions between oxygen, photosensitizer, and a special wavelength of light. However, a dosimetric predictor for PDT outcome is still elusive because current dosimetric quantities do not account for the differences in the PDT oxygen consumption rate for different fluence rates. In this study, we evaluate several dose metrics, total fluence, photobleaching ratio, PDT dose, and mean reacted singlet oxygen (mean [1 O2 ]rx ) for predicting the PDT outcome and a clinically relevant tumor re-growth endpoint. For this reason, radiation-induced fibrosarcoma (RIF) mice tumors are treated with 2-(1-Hexyloxyethyl)-2-devinyl pyropheophorbide (HPPH) and different in-air fluences (30 J/cm2 , 50 J/cm2 , 135 J/cm2 , 250 J/cm2 , and 350 J/cm2 ) and in-air fluence rates (20, 50, 75, 150 mW/cm2 ). Explicit measurements of HPPH and oxygen concentration as well as tissue optical properties are performed pre- and post-treatment. Then, this information is incorporated into a macroscopic model to calculate the photobleaching, PDT dose, and mean [1 O2 ]rx . Changes in tumor volume are tracked following the treatment and compared with the dose metrics. The correlation demonstrates that mean [1 O2 ]rx  serves as a better dosimetric quantity for predicting treatment outcome and a clinically relevant tumor re-growth endpoint.

[The Chernobyl Disaster Consequences from the -Distance of 30 Years]

There are 2 most important questions regarding studies of the Chernobyl disaster: to what degree the opportunities to decrease injuries of the people affected by the disaster were realized and how the study of the con- sequences of the disaster impacted elucidation of low level radiation damage to human health. It can be as- sumed that not all scientific elaborations were realized to a proper degree (the use of iodine prophylaxis, radioprotectors). It was associated with impoper fulfillment of instructions by executive organs of radiation safety and medical emergency aid. However, the stationary medical treatment of patients with acute radiation disease was well organized. Insufficient consideration was given to non- radiological factors having an effect or,the psycho-emotional state of the people. Harmful effects of small doses on human health were not be found. The adverse delayed consequences (thyroid cancer, leucosis, and solid cancers) were found in the case of exceeding dose limit of 250 mGy. The upper border of low harmless.radiation doses could not be detected in those studies because of poor radiation dosimetry of liquidators, inadequate models of risk evaluation and ignoring influence of non-radiological factors on human health.

Photodynamic therapy for the treatment of microinvasive squamous cell carcinoma of the lower lip: a case report

Photodynamic therapy (PDT) with methyl aminolevulinate (MAL) is approved in Europe for the treatment of actinic keratosis and Bowen's disease, both intraepithelial forms of squamous cell carcinoma (SCC). A therapeutic effect of MAL-PDT has been recently suggested for superficial, microinvasive and well-differentiated cutaneous SCC. We describe the successful use of MAL-PDT in a recently observed patient with microinvasive SCC of the lower lip and review published data on the use of PDT with MAL or d-aminolevulinic acid (ALA) in cutaneous microinvasive SCC. A patient with a biopsy-proven recurrent microinvasive SCC of the lower lip was treated with 2 cycles of MAL-PDT. Complete clinical, dermoscopic and histopathological clearance was obtained after 2 cycles of MAL-PDT with an excellent cosmetic result and a sustained remission after 24-month follow-up. A review of the few studies reporting on the use of MAL-PDT or ALA-PDT for cutaneous microinvasive SCCs was carried out. MAL-PDT might represent a non-invasive treatment option for microinvasive SCC of the lower lip if patients are not eligible for surgery. Post-treatment histopathological confirmation and a long-term follow-up are strictly recommended.

Radiation-induced Chondrosarcoma of the Bladder. Case Report and Review of Literature

BACKGROUND

Chondrosarcoma of the bladder is an extremely rare disease. Only five previously described cases are known in the medical literature.

PATIENTS AND METHODS

We present a chondrosarcoma developed 19 years after radiation treatment in a 73-year-old patient. A literature search of articles published from 1984 to 2014 was performed.

RESULTS

This is the first reported case of post-radiation bladder chondrosarcoma. We compared the clinicopathological features of the previously reported cases and reviewed the medical literature of the bladder sarcomas and post-radiation sarcomas.

CONCLUSION

The primary treatment for bladder mesenchymal neoplasms is surgical, preferably radical cystectomy with or without chemotherapy. Positive surgical margin is one of the most important factors negatively affecting disease-specific, recurrence-free and overall survival rates.

Impact of Nagasaki atomic bomb exposure on myelodysplastic syndrome patients who are treated with azacitidine

BACKGROUND/AIM

High-dose radiation exposure greatly increases the risk of myelodysplastic syndromes (MDS), however the clinical characteristics of MDS among atomic bomb survivors have not been thoroughly investigated to date. We designed this study to identify these characteristics.

PATIENTS AND METHODS

We retrospectively evaluated data from 13 atomic bomb survivors with MDS and 15 elderly patients with de novo MDS who were diagnosed between April 2011 and April 2013 at the Nagasaki Genbaku Hospital. All patients were treated with azacitidine (AZA; a hypomethylating agent) and overall survival rates were estimated.

RESULTS

No clear difference was observed in the clinical response to AZA between the two groups. However, atomic bomb survivors had a survival disadvantage, independent of their karyotype.

CONCLUSION

Minute genetic alterations caused by exposure to atomic radiation can adversely affect the response to AZA, even 66 years after the exposure. Further studies are required to clarify the mechanisms underlying this phenomenon.

The melanoma revolution: from UV carcinogenesis to a new era in therapeutics

Melanoma, the deadliest form of skin cancer, is an aggressive disease that is rising in incidence. Although melanoma is a historically treatment-resistant malignancy, in recent years unprecedented breakthroughs in targeted therapies and immunotherapies have revolutionized the standard of care for patients with advanced disease. Here, we provide an overview of recent developments in our understanding of melanoma risk factors, genomics, and molecular pathogenesis and how these insights have driven advances in melanoma treatment. In addition, we review benefits and limitations of current therapies and look ahead to continued progress in melanoma prevention and therapy. Remarkable achievements in the field have already produced a paradigm shift in melanoma treatment: Metastatic melanoma, once considered incurable, can now be treated with potentially curative rather than palliative intent.

Therapeutic and immune effects of 5-aminolevulinic acid photodynamic therapy on UVB-induced squamous cell carcinomas in hairless mice

The therapeutic effects of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) on cutaneous squamous cell carcinoma (SCC) are not fully understood, and the usefulness of topical PDT in the treatment of SCC is still debatable. The most interesting aspect in SCC PDT is perhaps its potential in inducing antitumor immune responses. In this study, cutaneous SCCs were established by UVB irradiation of hairless mice and treated with multiple ALA PDT. Immunohistochemistry assays showed that ALA PDT could induce quick apoptosis, overexpression of TNFα and marked increases in DCs, CD4(+) and CD8(+) cells in tumor interstitium and subcutaneous connective tissues. However, a complete response was only achieved for small SCCs. The clinical value of ALA PDT-induced specific antitumor immune responses in long-term control of SCCs deserves further study.

Risk of treatment-related esophageal cancer among breast cancer survivors

BACKGROUND

Radiotherapy for breast cancer may expose the esophagus to ionizing radiation, but no study has evaluated esophageal cancer risk after breast cancer associated with radiation dose or systemic therapy use.

DESIGN

Nested case-control study of esophageal cancer among 289 748 ≥5-year survivors of female breast cancer from five population-based cancer registries (252 cases, 488 individually matched controls), with individualized radiation dosimetry and information abstracted from medical records.

RESULTS

The largest contributors to esophageal radiation exposure were supraclavicular and internal mammary chain treatments. Esophageal cancer risk increased with increasing radiation dose to the esophageal tumor location (P(trend )< 0.001), with doses of ≥35 Gy associated with an odds ratio (OR) of 8.3 [95% confidence interval (CI) 2.7-28]. Patients with hormonal therapy ≤5 years preceding esophageal cancer diagnosis had lower risk (OR = 0.4, 95% CI 0.2-0.8). Based on few cases, alkylating agent chemotherapy did not appear to affect risk. Our data were consistent with a multiplicative effect of radiation and other esophageal cancer risk factors (e.g. smoking).

CONCLUSIONS

Esophageal cancer is a radiation dose-related complication of radiotherapy for breast cancer, but absolute risk is low. At higher esophageal doses, the risk warrants consideration in radiotherapy risk assessment and long-term follow-up.

Time and dose-response effects of honokiol on UVB-induced skin cancer development

Honokiol has shown chemopreventive effects in chemically-induced and UVB-induced skin cancer in mice. In this investigation, we assessed the time-effects of a topical low dose of honokiol (30 μg), and then the effects of different honokiol doses (30, 45, and 60 μg) on a UVB-induced skin cancer model to find an optimal dose and time for desirable chemopreventive effects. UVB radiation (30 mJ/cm(2), 5 days/week for 25 or 27 weeks) was used to induce skin carcinogenesis in SKH-1 mice. For the time-response experiment 30 μg honokiol in acetone was applied topically to the animals before the UVB exposure (30 min, 1 h, and 2 h) and after the UVB exposure (immediately, 30 min, and 1 h). Control groups were treated with acetone. For the dose-response study, animals were treated topically with acetone or honokiol (30, 45, and 60 μg) one hour before the UVB exposure. In the time-response experiment, honokiol inhibited skin tumor multiplicity by 49-58% while reducing tumor volumes by 70-89%. In the dose-response study, honokiol (30, 45, and 60 μg) significantly decreased skin tumor multiplicity by 36-78% in a dose-dependent manner, while tumor area was reduced by 76-94%. Honokiol (60 μg) significantly reduced tumor incidence by 40% as compared to control group. Honokiol applied in very low doses (30 μg) either before or after UVB radiation shows chemopreventive effects. Honokiol (30, 45, and 60 μg) prevents UVB-induced skin cancer in a dose-dependent manner. Honokiol can be an effective chemopreventive agent against skin cancer.

Merkel cell carcinoma: case report and literature review

BACKGROUND

Merkel cell carcinoma is an aggressive neuroendocrine cell carcinoma arising in the epidermis of patients aged >60 years. This lesion is found in sun-exposed areas and presents as a small violet raised nodule. It is usually painless and rapidly growing. Although its clinical presentation and characteristic histology are usually sufficient, immunohistochemical features are helpful in making an accurate diagnosis.

CLINICAL CASE

We present the case of a 62-year-old male with epidermoid carcinoma of the lung who was treated with surgery and local radiation for 2 months. He presented a painless 8-cm subcutaneous mass of some weeks of evolution, without inflammatory signs. Computerized tomography demonstrated a mass of probable lymph node origin. Fine-needle aspiration biopsy (FNAB) reported malignant cells and excisional surgery of the mass was performed, revealing a subcutaneous Merkel cell carcinoma.

CONCLUSIONS

Merkel cell carcinoma is a rare entity that develops in mature patients, often in sun-exposed areas, and presents cutaneous injury in intact skin. Definitive diagnosis is done using immunohistochemistry.

Primary cutaneous marginal zone lymphoma as a complication of radiation therapy: Case report and review

BACKGROUND

The occurrence of primary cutaneous B-cell lymphoma at the site of radiation therapy is exceptional. We report herein the case of a primary cutaneous marginal zone lymphoma arising at the site of radiotherapy for breast cancer.

METHODS/RESULTS

A seventy-year-old woman was diagnosed in 2005 with an invasive ductal carcinoma of the left breast, which was treated with surgery, adjuvant chemotherapy, and radiation therapy. Three years later she developed several cutaneous nodules on her left breast, followed by similar lesions on her back. Histologic, immunohistochemistry, and molecular findings were consistent with the diagnosis of cutaneous marginal zone lymphoma. Physical examination was otherwise negative, as well as mammography, total body CT, bone marrow biopsy, and Borrelia serology.

CONCLUSIONS

To our knowledge, this is the first published case of primary cutaneous marginal zone lymphoma occurring at the site of radiotherapy. Cutaneous surveillance is proposed from the first year after irradiation in order to detect new primary malignancies, including this rare cutaneous neoplasm.