Tumor-Induced Myeloid Cells Are Reduced by Gemcitabine-Loaded PAMAM Dendrimers Decorated with Anti-Flt1 Antibody.

While reshaping their microenvironment, tumors are also capable of influencing systemic processes including myeloid cell production. Therefore, the tumor-induced myeloid cells, such as myeloid-derived suppressor cells (MDSCs), which are characterized with pro-cancer properties, became another target in order to increase the success of the therapy. This study evaluated the capacity of a novel dendrimeric drug delivery platform to eliminate tumor-induced myeloid cells. As described in a previous study by our research group, the anti-Flt1 antibody-conjugated polyethylene glycol (PEG)-cored poly(amidoamine) (PAMAM) dendrimers improved the efficacy of gemcitabine against pancreatic cancer. Here, the biodistribution studies showed that these dendrimeric structures accumulated in the compartments that became rich in myeloid cells in the pancreatic tumor-bearing mice. When gemcitabine was loaded into the dendrimer complexes, the number of myeloid cells was significantly reduced while the percentage distribution of granulocytic and monocytic myeloid cells was not always significantly altered. The CD11b+Ly6G-Ly6C+ monocytes were more severely affected by the treatments than CD11b+Ly6G+Ly6C+ granulocytes. Immune infiltration levels in the tumor tissue were also altered. Myeloid cells in the spleen and F4/80+ macrophages of the liver were protected. The compartments, such as the liver and the bone marrow, which are known to have high vascular endothelial growth factor (VEGF)-Flt1 pathway activity, were particularly targeted by gemcitabine when delivered through anti-Flt1 antibody-conjugated PAMAM dendrimers. In conclusion, chemotherapeutic agents complexed with dendrimers not only improve anticancer efficacy, but they also assist in the elimination of the tumor-induced myeloid cells.

Impact of repeated abdominal surgery on wound healing and myeloid cell dynamics.

BACKGROUND: Even though wound dehiscence is a surgical complication, under certain medical conditions, repetition of the laparotomy (LT) (relaparotomy) can become inevitable. In addition to the risks associated with this surgical operation, relaparotomy can interfere with the tissue healing and contribute to the development of chronic wounds. METHODS: In an experimental relaparotomy wounding model, this study investigated the impact of repeated surgery on wound healing and on the immune cells of myeloid origin. RESULTS: The first repeat of the LT triggered fibrosis and marginally interfered with the wound healing; however, the second operation completely abrogated the healing process. Splenomegaly was observed as an indicator of the chronic inflammation and the systemic effect of repeated laparotomies. In the blood stream, the spleen, and the liver, these repeated surgeries exhibited a major impact on the CD11b+Ly6C+Ly6G- monocytes. On the other hand, especially, whespecially the second relaparotomy resulted in a massive purging of neutrophil granulocytes into the circulation. These CD11b+Ly6C+Ly6G+ neutrophils that were disseminated on repeated abdominal laparotomies had a proinflammatory character that positively influenced T cell proliferation and displayed a high capacity for production of reactive oxygen species. CONCLUSIONS: The repetition of abdominal LT not only interferes with the wound healing but also contributes to the development of imperfectly healing wounds which have systemic impact on immune compartments.

Splenectomy-Induced Leukocytosis Promotes Intratumoral Accumulation of Myeloid-Derived Suppressor Cells, Angiogenesis and Metastasis.

BACKGROUND: Enlargement of the spleen is commonly observed in animal models of cancer. Here, in a breast cancer model, it was aimed to determine the effect of splenectomy on circulating and tumor-infiltrating myeloid-derived suppressor cells (MDSCs), tumor angiogenesis, and metastasis. METHODS: Mice were inoculated with 4T1 breast cancer cells and underwent splenectomy or sham laparotomy. Tumor growth and survival of animals were followed. Macroscopic and histopathological analyses were performed to determine splenomegaly and metastasis. Immunophenotyping of myeloid cells was performed with flow cytometric analysis of CD11b, Gr-1, F4/80, CD206, CD11c, and F4/80 markers. Suppressive function of MDSCs on T cell proliferation was studied in cocultures. Tumor angiogenesis and granulocytic myeloid cell infiltration in the metastatic foci were studied by CD31 and Ly6G immunohistochemistry, respectively. RESULTS: The mice bearing breast tumors underwent total splenectomy at an early time point of tumorigenesis when only low levels of MDSCs had accumulated in the spleen. Circulating and tumor-infiltrating MDSCs, and tumor-associated macrophages (TAMs) were increased following splenectomy. Nevertheless, splenectomy could only lead to a temporary deceleration in tumor growth but favored lung metastasis and angiogenesis in the long run. CONCLUSION: Our data demonstrated a link among splenectomy-induced leukocytosis, accumulation of circulating and tumor-infiltrating MDSC, and enhanced angiogenesis and metastasis. Therefore, as a part of oncological surgery, favorable and unfavorable facets of the splenectomy must be considered to improve therapeutic efficacy.

Low serum vitamin D levels are associated with severe histological features and poor response to therapy in patients with autoimmune hepatitis.

BACKGROUND AND AIM: 25-Hydroxyvitamin D [25(OH)D] has an important role in fibrosis progression and inflammatory response in patients with various etiologies of chronic liver disease. However, its influence on autoimmune hepatitis (AIH) has not been investigated. We evaluated the association of serum 25(OH)D levels with clinical, biochemical and histological features and response to therapy in AIH. MATERIALS AND METHODS: Serum 25(OH)D levels were quantified in 68 therapy naïve AIH patients and 34 healthy controls. RESULTS: Mean serum 25(OH)D levels were significantly lower in AIH compared to healthy controls (16.8 ± 9.2 vs. 35.7 ± 13.6, p < 0.0001). Low levels of 25(OH)D (<30 µg/L) were independently associated with advance fibrosis and severe interface hepatitis in AIH patients [p = 0.014; odds ratio (OR) 0.12, 95% confidence interval (CI) 0.02-0.65 and p = 0.020; OR 0.17, 95% CI 0.04-0.76, respectively]. Severe 25(OH)D deficiency (<10 µg/L) was associated with advance fibrosis, severe interface hepatitis, low platelet counts and sampling time in a univariate analysis. Only interface hepatitis and fibrosis scores were independently associated with 25(OH)D deficiency in a multiple regression analysis (p = 0.005; OR 0.12, 95% CI 0.03-0.53 and p = 0.022; OR 0.15, 95% CI 0.03-0.75, respectively). Mean serum 25(OH)D levels were lower in non-responders compared to responders (9.2 ± 4.8 vs. 17.1 ± 9.4, p = 0.015), and 25(OH)D deficiency was more commonly observed in non-responders than the responders (80 vs. 43%, p = 0.036). CONCLUSIONS: Low 25(OH)D levels are associated with advance fibrosis and severe inflammation in AIH. Our study suggests that vitamin D may be a potential biomarker that predicts response to therapy and histological features in AIH.

Diagnostic and therapeutic evaluation of folate-targeted paclitaxel and vinorelbine encapsulating theranostic liposomes for non-small cell lung cancer.

NSCLC is the most common type of lung cancer. However, non-specific contrast agents, radiopharmaceuticals, and treatment methods are insufficient in early diagnosis and eradication of all tumor tissue. Therefore, the formulation of a novel, targeted, specific theranostic agents possess critical importance. In our previous study, paclitaxel and vinorelbine encapsulating, Tc-99m radiolabeled, folate targeted, nanosized liposomes were formulated and found promising due to characterization properties, high cellular uptake, and cytotoxicity. In this study, in vivo therapeutic and diagnostic efficacy of liposomal formulations were tested by biodistribution study, evaluation of tumor growth inhibition, and histopathologic examination after in vitro assays on LLC1 cells. Both actively and passively targeted liposomal formulations exhibited high cellular uptake, and co-drug encapsulating liposomes showed a greater cytotoxicity profiles than free drug combination in LLC1 cells. By the results of biodistribution studies performed in NSCLC tumor-bearing C57BL/6 mice, the uptake of radiolabeled, actively folate targeted, co-drug encapsulating liposomal formulation was found to be higher in tumor tissue when compared to non-actively targeted one. Also, more effective treatment was achieved by using folate-targeted, co-drug encapsulating liposomal formulation when compared to free drugs combination according to changes in tumor size of mice. Furthermore, liposomal formulations showed lower toxicity compared to free drug combinations in the toxicity study considering body weight. Moreover, according to the histopathological study, folate targeted, co-drug encapsulating liposomes not only inhibited the tumor growth effectively but also restricted the lung metastasis entirely.

Prevalence of Epidermal Growth Factor Receptor Mutations in Patients with Non-Small Cell Lung Cancer in Turkish Population.

AIMS: Epidermal growth factor receptor mutation analysis in non-small cell lung cancer is important for selecting patients who will receive treatment with tyrosine kinase inhibitors. In this study, we aimed to investigate the prevalence of epidermal growth factor receptor mutations and mutation patterns in the Turkish population. METHODS: We retrospectively reviewed molecular pathology reports of 959 cases with lung cancer analysed for epidermal growth factor receptor mutations. We analysed all four epidermal growth factor receptor exon mutations using a real-time polymerase chain reaction platform. RESULTS: In this study, the epidermal growth factor receptor mutation rate in the Turkish population was 16.7% (160 of 959). The epidermal growth factor receptor mutation frequency was significantly higher in women (37.1%, n=96) than in men (9.1%, n=64) (p<0.001). In addition, the epidermal growth factor receptor mutation rate was higher in the adenocarcinoma histologic type (p<0.001). Patients with mutations were older than those without mutations (p=0.003). The most frequent mutations were exon 19 deletions (48.8%, 78/160) and exon 21 L858R point mutations (38.1.1%, 61/160). We also detected compound mutation patterns in three cases (1.9%). CONCLUSION: The prevalence of epidermal growth factor receptor mutations in the Turkish population was slightly higher than that in the Caucasian population and lower than that in the East Asian population. The results of this study may provide guidance in personalized therapy of non-small cell lung cancer in the Turkish population.

Bone marrow fibrosis may be an effective independent predictor of the 'TKI drug response level' in chronic myeloid leukemia.

OBJECTIVES: The aim of this study was to assess bone marrow (BM) fibrosis and dysplasia in chronic myeloid leukemia (CML) patients receiving the first-generation tyrosine kinase inhibitor (TKI), imatinib, or second-generation TKIs, dasatinib, and nilotinib. We further investigated whether CML under TKI is associated with dysplastic BM changes during the clinicopathological course of the disease. METHODS: In total, pre-treatment BM paraffin blocks of biopsy specimens were available for 41 adult patients diagnosed with chronic phase CML. Post-treatment BM aspirate clot and core biopsy samples were reviewed for fibrosis and dyshematopoiesis. RESULTS: Overall, 13 (31.7%) patients achieved a complete cytogenetic response with imatinib treatment, with no events. In 25 patients, imatinib was discontinued owing to primary or secondary resistance. In patients with initial dysmyelopoiesis, the rate of BM fibrosis was 82.4 versus 47.6% for other patient groups (P = 0.02). Overall, 24 patients with newly diagnosed CML showed marrow fibrosis, among which 19 (79.1%) had imatinib resistance. However, only 5 out of 15 patients (33.5%) without marrow fibrosis had imatinib resistance (P = 0.08). Discussion Our findings indicate that BM fibrosis is an independent predictor of the 'TKI drug response level' in CML and support its inclusion as a critical pathobiological parameter for decision-making with regard to TKI drug selection de novo, calculation of prognosis at the onset of disease, and monitoring response to TKI in the long-term disease course of CML.