Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is one of the most commonly applied methods for lateral trace element distribution analysis in medical studies. Many ...improvements of the technique regarding quantification and achievable lateral resolution have been achieved in the last years. Nevertheless, sample preparation is also of major importance and the optimal sample preparation strategy still has not been defined. While conventional histology knows a number of sample pre-treatment strategies, little is known about the effect of these approaches on the lateral distributions of elements and/or their quantities in tissues. The technique of formalin fixation and paraffin embedding (FFPE) has emerged as the gold standard in tissue preparation. However, the potential use for elemental distribution studies is questionable due to a large number of sample preparation steps. In this work, LA-ICP-MS was used to examine the applicability of the FFPE sample preparation approach for elemental distribution studies. Qualitative elemental distributions as well as quantitative concentrations in cryo-cut tissues as well as FFPE samples were compared. Results showed that some metals (especially Na and K) are severely affected by the FFPE process, whereas others (e.g., Mn, Ni) are less influenced. Based on these results, a general recommendation can be given: FFPE samples are completely unsuitable for the analysis of alkaline metals. When analyzing transition metals, FFPE samples can give comparable results to snap-frozen tissues.
Graphical abstract
Sample preparation strategies for biological tissues are compared with regard to the elemental distributions and average trace element concentrations.
Current treatment guidelines refer to small cell lung cancer (SCLC), one of the deadliest human malignancies, as a homogeneous disease. Accordingly, SCLC therapy comprises chemoradiation with or ...without immunotherapy. Meanwhile, recent studies have made significant advances in subclassifying SCLC based on the elevated expression of the transcription factors ASCL1, NEUROD1, and POU2F3, as well as on certain inflammatory characteristics. The role of the transcription regulator YAP1 in defining a unique SCLC subset remains to be established. Although preclinical analyses have described numerous subtype-specific characteristics and vulnerabilities, the so far non-existing clinical subtype distinction may be a contributor to negative clinical trial outcomes. This comprehensive review aims to provide a framework for the development of novel personalized therapeutic approaches by compiling the most recent discoveries achieved by preclinical SCLC research. We highlight the challenges faced due to limited access to patient material as well as the advances accomplished by implementing state-of-the-art models and methodologies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
Pulmonary metastasectomy is an integral part of the interdisciplinary treatment of patients with pulmonary metastases (PMs) from colorectal carcinoma (CRC). Although alterations in the ...epidermal growth factor receptor (EGFR) pathway are common in CRC, there is still insufficient data regarding PM. We hypothesized that EGFR expression and Kirsten rat sarcoma viral oncogene homolog (
KRAS
)/
BRAF
mutations (Mts) might be associated with clinicopathological variables and the outcome in patients undergoing pulmonary metastasectomy.
Methods
In this single-center study, 44 patients undergoing pulmonary metastasectomy from primary CRC were included and prospectively followed up. Tissue specimens of resected PMs were assessed. Restriction fragment length analysis was used for
BRAF V600E
and
KRAS
codons 12 and 13 Mt analyses. EGFR expression was evaluated by immunohistochemistry. Patients were followed up in 3–6-month intervals.
Results
EGFR expression was evident in 49 % of the PMs, whereas Mts in
KRAS
and
BRAF
were detected in 48 and 0 %, respectively. Time to lung-specific recurrence after metastasectomy was significantly decreased in patients with
KRAS
mutated PMs in univariate (
p
= 0.013) and multivariate analysis (
p
= 0.035), whereas EGFR expression had no impact on recurrence free survival. Moreover, KRAS Mts were associated with the number of PMs (
p
= 0.037) and with the lung as first site of recurrence after metastasectomy (
p
= 0.047).
Discussion
This is the first evaluation of EGFR pathway alterations in the setting of pulmonary metastasectomy. Our data suggest that patients with
KRAS
Mts are at high risk for early pulmonary recurrence and have a more diffuse pattern of metastasis. These findings may have impact on the therapeutic management of CRC patients with pulmonary spreading.
The major aim of this study was to investigate the role of DNA methylation (referred to as methylation) on miRNA silencing in non-small cell lung cancers (NSCLC).
We conducted microarray expression ...analyses of 856 miRNAs in NSCLC A549 cells before and after treatment with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (Aza-dC) and with a combination of Aza-dC and the histone deacetylase inhibitor trichostatin A. miRNA methylation was determined in 11 NSCLC cell lines and in primary tumors and corresponding nonmalignant lung tissue samples of 101 patients with stage I-III NSCLC.
By comparing microarray data of untreated and drug-treated A549 cells, we identified 33 miRNAs whose expression was upregulated after drug treatment and which are associated with a CpG island. Thirty (91%) of these miRNAs were found to be methylated in at least 1 of 11 NSCLC cell lines analyzed. Moreover, miR-9-3 and miR-193a were found to be tumor specifically methylated in patients with NSCLC. We observed a shorter disease-free survival of patients with miR-9-3 methylated lung squamous cell carcinoma (LSCC) than patients with miR-9-3 unmethylated LSCC by multivariate analysis HR = 3.8; 95% confidence interval (CI), 1.3-11.2, P = 0.017 and a shorter overall survival of patients with miR-9-3 methylated LSCC than patients with miR-9-3 unmethylated LSCC by univariate analysis (P = 0.013).
Overall, our results suggest that methylation is an important mechanism for inactivation of certain miRNAs in NSCLCs and that miR-9-3 methylation may serve as a prognostic parameter in patients with LSCC.
Current therapy of KRAS-mutant lung cancer Ghimessy, Aron; Radeczky, Peter; Laszlo, Viktoria ...
Cancer and metastasis reviews,
12/2020, Letnik:
39, Številka:
4
Journal Article
Recenzirano
Odprti dostop
KRAS mutations are the most frequent gain-of-function alterations in patients with lung adenocarcinoma (LADC) in the Western world. Although they have been identified decades ago, prior efforts to ...target KRAS signaling with single-agent therapeutic approaches such as farnesyl transferase inhibitors, prenylation inhibition, impairment of KRAS downstream signaling, and synthetic lethality screens have been unsuccessful. Moreover, the role of KRAS oncogene in LADC is still not fully understood, and its prognostic and predictive impact with regards to the standard of care therapy remains controversial. Of note, KRAS-related studies that included general non-small cell lung cancer (NSCLC) population instead of LADC patients should be very carefully evaluated. Recently, however, comprehensive genomic profiling and wide-spectrum analysis of other co-occurring genetic alterations have identified unique therapeutic vulnerabilities. Novel targeted agents such as the covalent KRAS G12C inhibitors or the recently proposed combinatory approaches are some examples which may allow a tailored treatment for LADC patients harboring KRAS mutations. This review summarizes the current knowledge about the therapeutic approaches of KRAS-mutated LADC and provides an update on the most recent advances in KRAS-targeted anti-cancer strategies, with a focus on potential clinical implications.
In this study, we present a mechanism for the development of arterial blood supply in experimental liver metastases. To analyze the arterialization process of experimental liver metastases, we ...elucidated a few key questions regarding the blood supply of hepatic lobules in mice. The microvasculature of the mouse liver is characterized by numerous arterioportal anastomoses and arterial terminations at the base of the lobules. These terminations supply one hepatic microcirculatory subunit per lobule, which we call an arterial hepatic microcirculatory subunit (aHMS). The process of arterialization can be divided into the following steps: 1) distortion of the aHMS by metastasis; 2) initial fusion of the sinusoids of the aHMS at the tumor parenchyma interface; 3) fusion of the sinusoids located at the base of the aHMSs, which leads to the disruption of the vascular sphincter (burst pipe); 4) incorporation of the dilated artery and the fused sinusoids into the tumor; and 5) further development of the tumor vasculature (arterial tree) by proliferation, remodeling, and continuous incorporation of fused sinusoids at the tumor–parenchyma interface. This process leads to the inevitable arterialization of liver metastases above the 2000- to 2500-μm size, regardless of the origin and growth pattern of the tumor.
Lack of Angiogenesis in Experimental Brain Metastases Bugyik, Edina; Dezső, Katalin; Reiniger, Lilla ...
Journal of neuropathology and experimental neurology,
2011-November, Letnik:
70, Številka:
11
Journal Article
Recenzirano
Odprti dostop
Angiogenesis is believed to be essential for the growth of metastatic tumors in the brain. We analyzed the vascularization of tumors formed by 4 epithelial cell lines (C38, ZR75, HT25, and H1650) and ...a fibrosarcoma (HT1080) cell line injected into the brains of mice. No peritumoral angiogenesis was observed. Tumors apparently acquired their vasculature by incorporation of native vessels. Vessel density was lower, but vessel diameter and vascular cell proliferation were higher within all tumors versus those in the peritumoral tissue. There was an inverse correlation between the number of incorporated vessels and vascular cell proliferation. Epithelial tumors with pushing growth patterns had lower vessel density and elevated vascular cell proliferation compared with invasive tumors. The incorporated vessels retained their normal structure, with the exception of astrocyte foot processes that were replaced by tumor cells. Attachment to the vascular basement membrane led to the differentiation of the ZR75 breast cancer cells. In the HT1080 metastases, there was intussusceptive angiogenesis, that is, the fibrosarcoma cells that were attached to the vessel caused lumen splitting and filled the developing pillars. Branching angiogenesis was not observed either in the tumors or in control cerebral wounds. These data suggest that sprouting angiogenesis is not needed for the incipient growth of cerebral metastases and that tumor growth in this model is a result of incorporation of host vessels.
Malignant pleural mesothelioma (MPM) is an aggressive thoracic tumor type with limited treatment options and poor prognosis. The angiokinase inhibitor nintedanib has shown promising activity in the ...LUME-Meso phase II MPM trial and thus is currently being evaluated in the confirmatory LUME-Meso phase III trial. However, the anti-MPM potential of nintedanib has not been studied in the preclinical setting.
We have examined the antineoplastic activity of nintedanib in various
and
models of human MPM.
Nintedanib's target receptors were (co)expressed in all the 20 investigated human MPM cell lines. Nintedanib inhibited MPM cell growth in both short- and long-term viability assays. Reduced MPM cell proliferation and migration and the inhibition of Erk1/2 phosphorylation were also observed upon nintedanib treatment
Additive effects on cell viability were detected when nintedanib was combined with cisplatin, a drug routinely used for systemic MPM therapy. In an orthotopic mouse model of human MPM, survival of animals receiving nintedanib
showed a favorable trend, but no significant benefit. Nintedanib significantly reduced tumor burden and vascularization and prolonged the survival of mice when it was administered intraperitoneally. Importantly, unlike bevacizumab, nintedanib demonstrated significant
antivascular and antitumor potential independently of baseline VEGF-A levels.
Nintedanib exerts significant antitumor activity in MPM both
and
These data provide preclinical support for the concept of LUME-Meso trials evaluating nintedanib in patients with unresectable MPM.
.
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