Formin proteins in normal tissues and cancer

The actin cytoskeleton is a dynamic structure that determines cell shape. Actin turnover is mandatory for migration in normal and malignant cells. In epithelial cancers invasion is frequently accompanied by epithelial to mesenchymal transition (EMT). In EMT, cancer cells acquire a migratory phenotype through transcriptional reprogramming. EMT requires substantial re-organization of actin. During the past decade, new actin regulating proteins have been discovered. Among these are members of the formin family. To study formin expression in tissues and cells, antibodies for detection of formin proteins FMNL1 (Formin-like protein 1), FMNL2 (Formin-like protein 2) and FHOD1 (Formin homology 2 domain containing protein 1) were used. The expression of formins was characterized in normal tissues and selected cancers using immunohistochemistry. The functional roles of formins were studied in cancer cell lines. We found that FMNL2 is widely expressed. It is a filopodial component in cultured melanoma cells. In clinical melanoma, FMNL2 expression has prognostic significance. FHOD1 is a formin expressed in mesenchymal cell types. FHOD1 expression is increased in oral squamous cell carcinoma (SCC) EMT. Importantly, FHOD1 participates in invasion of cultured oral SCC cells. FMNL1 expression is low in normal epithelia, but high in leukocytes and smooth muscle cells. Expression of FMNL1 can be found in carcinoma; we detected FMNL1 expressing cells in basal type of breast cancer. Our results indicate that formins are differentially expressed in normal tissues and that their expression may shift in cancer. Functionally FMNL2 and FHOD1 participate in processes related to cancer progression. Studying formins is increasingly important since they are potential drug targets.Formiinit terveissä kudoksissa ja syövässä Solujen aktiinitukiranka on dynaaminen rakenne, joka määrää solujen muodon. Solujen liikkuminen ja syöpäsolujen invaasio edellyttää huomattavaa aktiinitukirangan muokkausta. Epiteeliperäisten syöpäsolujen invaasiokykyyn liittyy monesti epiteeli-mesenkymaalinen transitio (EMT). EMT on käsitteenä tunnettu yksilön kehitysbiologiasta, jossa se on välttämätön kehon osien ja kudosten muovautumisessa. Kehityksellistä prosessia muistuttavalla tavalla syöpäsolujen EMT:ssa transkriptio muuttuu, minkä seurauksena syöpäsolut irtoavat ympäristöstään, muuttuvat pitkänomaisiksi ja tehokkaasti liikkuviksi. Muutokset edellyttävät tehokasta aktiinisäikeiden muokkausta. Yksi aktiinitukirankaa muokkaavien proteiinien perheitä ovat formiinit. Ne ovat viimeisen vuosikymmenen aikana olleet aktiivisen tutkimuksen kohteena. Formiinien keskeinen toiminto on aktiinisäikeiden muodostaminen. Tutkiaksemme formiinien ilmentymistä kudoksissa, varmistimme kolmen formiinin vasta-aineen luotettavan toimivuuden. Vasta-aineet oli valmistettu formiinien FMNL1 (Formin-like protein 1), FMNL2 (Formin-like protein 2) ja FHOD1 (Formin homology 2 domain containing protein 1) immunohistokemialliseen tunnistamiseen. Näiden vasta-aineiden avulla kartoitimme formiinien ilmentymisprofiilit normaaleissa kudoksissa, ja jatkoimme tutkimalla niiden ilmentymistä syöpäkudoksissa ja funktiota viljellyissä syöpäsoluissa. Osoitimme että FMNL2 ilmentyminen on laajaa normaalikudoksissa. FMNL2 paikantuu solukalvon ulokkeisiin viljellyissä melanoomasoluissa, ja sillä on ennusteellinen merkitys kliinisessä melanoomassa. FHOD1 puolestaan ilmentyy mesenkymaalisissa kudoskomponenteissa. FHOD1 ilmentyminen nousee suun levyepiteelikarsinooman EMT:ssa. Saatoimme solukokein osoittaa, että FHOD1 osallistuu EMT:hen liitettyihin toimintoihin. Lopuksi tutkimme FMNL1 ilmentymistä, ja totesimme sen lähes rajoittuvan valkosoluihin ja sileälihassoluihin. Terveissä epiteeleissä FMNL1 ilmentyminen on vähäinen, mutta saattaa lisääntyä basaalisessa rintasyövässä. Tuloksemme osoittavat että formiinit ilmentyvät toisistaan poikkeavalla profiililla normaaleissa kudoksissa. Lisäksi niiden ilmentyminen voi muuttua syövässä. Viljellyissä syöpäsoluissa formiinit osallistuvat syövän progressioon eli invaasiokykyä ja metastasointia edistäviin toimintoihin. Formiinien tutkiminen syövässä on entistäkin tärkeämpää, koska niille on jo löytynyt pienimolekyläärinen inhibiittori. Formiinien toiminnan inhibointi saattaa tulevaisuudessa kehittyä osaksi syövän lääkkeellistä hoitoa.Siirretty Doriast

Clinically variable nemaline myopathy in a three-generation family caused by mutation of the skeletal muscle alpha-actin gene

We present here a Finnish nemaline myopathy family with a dominant mutation in the skeletal muscle alpha-actin gene, p.(Glu85Lys), segregating in three generations. The index patient, a 5-year-old boy, had the typical form of nemaline myopathy with congenital muscle weakness and motor milestones delayed but reached, while his mother never had sought medical attention for her very mild muscle weakness, and his maternal grandmother had been misdiagnosed as having myotonic dystrophy. This illustrates the clinical variability in nemaline myopathy. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

FHOD1 formin is upregulated in melanomas and modifies proliferation and tumor growth

The functional properties of actin-regulating formin proteins are diverse and in many cases cell-type specific. FHOD1, a formin expressed predominantly in cells of mesenchymal lineage, bundles actin filaments and participates in maintenance of cell shape, migration and cellular protrusions. FHOD1 participates in cancer associated epithelial to mesenchymal transition (EMT) in oral squamous cell carcinoma and breast cancer. The role of FHOD1 in melanomas has not been characterized. Here, we show that FHOD1 expression is typically strong in cutaneous melanomas and cultured melanoma cells while the expression is low or absent in benign nevi. By using shRNA to knockdown FHOD1 in melanoma cells, we discovered that FHOD1 depleted cells are larger, rounder and have smaller focal adhesions and inferior migratory capacity as compared to control cells. Importantly, we found FHOD1 depleted cells to have reduced colony-forming capacity and attenuated tumor growth in vivo, a finding best explained by the reduced proliferation rate caused by cell cycle arrest. Unexpectedly, FHOD1 depletion did not prevent invasive growth at the tumor margins. These results suggest that FHOD1 participates in key cellular processes that are dysregulated in malignancy, but may not be essential for melanoma cell invasion.Peer reviewe

Depression and Nigral Neuron Density in Lewy Body Spectrum Diseases

Parkinson's disease and other Lewy body spectrum diseases (LBDs) are associated with a specific risk for clinical depression. In the present clinicopathological study with 73 patients with LBD, we observed that the substantia nigra pars compacta dopamine neuron density was markedly lower in patients who had comorbid depression antemortem than in nondepressed patients (1.52 vs 2.32 n/mm(2), p = 0.004). There were no differences in cognition, motor disease severity, antiparkinsonian medications, or disease duration between groups. The results implicate the substantia nigra as an important psychomotor modulatory area of mood in patients with Lewy body disorders. ANN NEUROL 202

BRAF immunohistochemistry predicts sentinel lymph node involvement in intermediate thickness melanomas

Background Sentinel node biopsy (SNB) is an important step in melanoma staging and prognostication. It is commonly performed for patients with intermediate thickness melanomas, based on clinicopathological features. However, only 20-25% of patients eventually demonstrate nodal involvement. The aim of this study was to evaluate whether tissue biomarkers with links to melanoma biology, together with clinicopathological parameters, could aid in the prediction of sentinel node involvement and improve selection of patients for SNB. In addition, we examined the role of these clinical or biological markers in disease outcome. Methods We collected a case-control cohort of 140 intermediate thickness (Breslow 0,9-4,0mm) melanoma patients with or without SNB involvement matched for age, gender, Breslow thickness and location. From this cohort, we tested the predictive value of common clinicopathological parameters (ulceration, mitotic count and tumor regression) and FMNL-2, ezrin and BRAF V600E immunoreactivity, for sentinel node involvement and survival. We further analyzed the correlations in the superficial spreading melanoma subtype. Results Based on our case control analysis, of the markers, BRAF V600E status (p = 0.010) and mitotic count (p = 0.036) correlated with SNB involvement. SNB status was a strong independent prognosticator for recurrence free survival (RFS p Conclusions These results demonstrate that BRAF immunohistochemistry could serve as a useful addition to a marker panel for selecting intermediate thickness melanoma patients for SNB.Peer reviewe

The m.7510T > C mutation: Hearing impairment and a complex neurologic phenotype

Objectives: Mutations in mitochondrial DNA cause a variety of clinical phenotypes ranging from a mild hearing impairment (HI) to severe encephalomyopathy. The MT-TS1 gene is a hotspot for mutations causing HI. The m.7510T>C mutation in MT-TS1 has been previously associated with non-syndromic HI in four families from different ethnic backgrounds.Materials and Methods: We describe the clinical, genetic, and histopathological findings in a Finnish family with the heteroplasmic m.7510T>C mutation in mitochondrial DNA.ResultsThe family proband presented with a progressive mitochondrial disease phenotype including migraine, epilepsy, mild ataxia, and cognitive impairment in addition to HI. One young adult presented with HI only. Other family members had a mild phenotype comprising ataxia and tremor in addition to HI. Mutation heteroplasmy was 90% in the blood of maternal grandmother and 99% in the muscle and blood of the three other family members. Muscle histology was consistent with mitochondrial myopathy in three family members. The mitochondrial haplogroup of the family was a different branch of the haplogroup H than in the previous reports of this mutation.Conclusion: Our results suggest that, in addition to sensorineural HI, the m.7510T>C mutation is associated with a spectrum of mitochondrial disease clinical features including migraine, epilepsy, cognitive impairment, ataxia, and tremor, and with evidence of mitochondrial myopathy

Negative C-11-PIB PET Predicts Lack of Alzheimer's Disease Pathology in Postmortem Examination

Our aim was to assess whether in vivo C-11-PIB negative memory-impaired subjects may nonetheless exhibit brain Alzheimer's disease (AD) pathology. We re-evaluated the PET images and systematically characterized the postmortem neuropathology of six individuals who had undergone clinically indicated amyloid PET. The single case with negligible amyloid-beta (A beta) pathology had Lewy body disease, where concomitant AD changes are often seen. Further, the subject's plaques were predominantly diffuse. The predictive value of a negative C-11-PIB scan appears to be good, even in memory-impaired populations. Our results suggest that considerable neuritic A beta plaque pathology in the absence of specific/cortical C-11-PIB binding upon PET is unlikely

Height and nigral neuron density in Parkinson's disease

Background: The dopaminergic system modulates growth hormone secretion and previous results have suggested a link between short stature and an increased risk of Parkinson's disease (PD).Methods: In 36 Lewy body spectrum disease (LBD) cases (PD = 22) and 19 controls, nigral TH-positive neuron densities were measured postmortem from midbrain sections and corrected with the Abercrombie method. Body measurements were collected from autopsies or patient records. Our aim was to investigate the possible relationship between height and the density of neurons in the substantia nigra pars compacta (SNc).Results: SNc neuron density (n/mm2) had an inverse association with height, (R2 = 0.317, p Conclusions: Individual adult height may be connected to nigral neuron numbers in patients with LBDs, including PD.</p

FMNL2/FMNL3 formins are linked with oncogenic pathways and predict melanoma outcome

While most early (stage I-II) melanomas are cured by surgery, recurrence is not uncommon. Prognostication by current clinicopathological parameters does not provide sufficient means for identifying patients who are at risk of developing metastases and in need of adjuvant therapy. Actin-regulating formins may account for invasive properties of cancer cells, including melanoma. Here, we studied formin-like protein 2 and 3 (FMNL2 and FMNL3) in melanoma by analysing their role in the invasive properties of melanoma cells and by evaluating whether FMNL2 expression is associated with melanoma outcome. Immunohistochemical characterization of FMNL2 in a cohort of 175 primary cutaneous stage I-II melanomas indicated that high FMNL2 reactivity correlates with poor outcome as evaluated by recurrence free survival (p < 0.0001) or disease specific survival (p < 0.0001). In multivariate analysis, Breslow's thickness (p < 0.05) and FMNL2 expression (p < 0.001) remained as independent prognostic factors. Cellular studies revealed that FMNL2 is a component of filopodia in many melanoma cell lines. Inhibition of either FMNL2 or the closely related FMNL3 affected the maintenance of melanoma cell morphology and reduced migration. Finally, inhibition of the BRAF, PI3K and MAPK oncogenic pathways markedly reduced expression of both FMNL2 and FMNL3 in melanoma cells. The results suggest a major role for FMNL2/FMNL3 formins in melanoma biology and raise the possibility that the novel targeted melanoma drugs may interfere with the cellular properties regulated by these formins. </p