Cavin-1 and Caveolin-1 are both required to support cell proliferation, migration and anchorage-independent cell growth in rhabdomyosarcoma

Abstract

Rhabdomyosarcoma (RMS) is a childhood soft tissue tumor with broad expression of markers that are typically found in skeletal muscle. Cavin-1 is a recently discovered protein actively cooperating with Caveolin-1 (Cav-1) in the morphogenesis of caveolae and whose role in cancer is drawing increasing attention. Using a combined in silico and in vitro analysis here we show that Cavin-1 is expressed in myogenic RMS tumors as well as in human and primary mouse RMS cultures, exhibiting a broad subcellular localization, ranging from nuclei and cytosol to plasma membrane. In particular, the coexpression and plasma membrane interaction between Cavin-1 and Cav-1 characterized the proliferation of human and mouse RMS cell cultures, while a downregulation of their expression levels was observed during the myogenic differentiation. Knockdown of Cavin-1 or Cav-1 in the human RD and RH30 cells led to impairment of cell proliferation and migration. Moreover, loss of Cavin-1 in RD cells impaired the anchorage-independent cell growth in soft agar. While the loss of Cavin-1 did not affect the Cav-1 protein levels in RMS cells, Cav-1 overexpression and knockdown triggered a rise or depletion of Cavin-1 protein levels in RD cells, respectively, in turn reflecting on increased or decreased cell proliferation, migration and anchorage-independent cell growth. Collectively, these data indicate that the interaction between Cavin-1 and Cav-1 underlies the cell growth and migration in myogenic tumors. Rhabdomyosarcoma (RMS) is a childhood soft tissue sarcoma exhibiting broad expression of skeletal muscle markers, 1-3 such as Pax7, MyoD, Myogenin, desmin and muscle-specific actin. 4,5 Cells of origin in RMS may be different muscular and non-muscular cell precursors, 6-8 such as muscle satellite cells (SCs), 9-11 and myoblasts 9,10,12-14 or adipocytes, 15 which are responsible of two major histological subtypes known as embryonal (ERMS) and alveolar (ARMS). The most common ERMS variant arises in children usually o5 years on distinct body sites, such as head, neck and genitourinary regions, while ARMS typically arises in the muscular limb extremities of adolescents and is characterized by poorer prognosis. 16 The genomic landscape causative of ERMS is characterized by a number of genetic lesions and/or somatic mutations that deliberately sustain the activity of different receptors, such as IGF1R, FGFR4 and Patched, 17-21 and related downstream pathways (i.e., RAS/ERK, PI3K/AKT and Sonic Hedgehog signaling). 11,22 In addition, defects in tumor suppressors (i.e., p53), 23 cell cycle regulatory genes (i.e., N-Myc, Rb1) 21,24 and structural proteins involved in muscular integrity (i.e., dystrophin, alpha-sarcoglycan and dysferlin) have been reported. [25][26][27][28][29][30] Conversely, ARMS is dominated by the presence of specific chromosomal translocations leading to expression of the fused Pax3-Foxo1 and Pax7-Foxo1 factors, that driving in a cell cycle manner the transcription of several genes normally restricted to the embryonal development f...

Downregulation of Cavin‐1 Expression via Increasing Caveolin‐1 Degradation Prompts the Proliferation and Migration of Vascular Smooth Muscle Cells in Balloon Injury–Induced Neointimal Hyperplasia

“…Since Cavin‐1 and CAV‐1 always interrelated together and influenced each other, knocking down either Cavin‐1 or CAV‐1 is responsible for the decrease in expression of the other protein. Moreover, a recent study has shown that Cavin‐1 and CAV‐1 are both required for cell proliferation and migration in rhabdomyosarcoma and indicated that the cooperation between Cavin‐1 and CAV‐1 underlies the cell growth in myogenic tumors . In the present study, we found that decreased Cavin‐1 expression did not inhibit the CAV‐1 mRNA at the transcript level, which was confirmed using the Cavin‐1 knockout mice .…”

Caveolin-1 in the regulation of cell metabolism: a cancer perspective

“…Consequently, CAV1 was found to be overexpressed in cancers of liver, colon, breast, kidney, lung, among others [29], and acts as a tumour promoter or suppressor depending on tumour type and stage [23, 33]. Regarding its tumour promoting function, it has been reported that high expression of CAV1 drives tumourigenesis by inhibiting apoptosis, facilitating anchorage-independent growth, drug resistance as well as metastasis [30, 33–39]. For instance, CAV1 expression in liver cancer patients was found to positively correlate with differentiation status, increased portal vein invasion, intrahepatic metastasis, and to predict overall survival outcome [37].…”

MURC/cavin-4 Is Co-Expressed with Caveolin-3 in Rhabdomyosarcoma Tumors and Its Silencing Prevents Myogenic Differentiation in the Human Embryonal RD Cell Line

“…In vitro studies were conducted using the human embryonal RD cells, RD12, RD18 and alveolar RH30 cells, as described in [50]; the primary mouse embryonal U57810 and alveolar U23674 cultures were derived from transgenic mice in which either p53 loss or concomitant p53 loss and Pax3-Foxo1 knock-in was restricted to Myf6 (myogenic factor 6)-positive myoblasts, respectively [53, 54]. Cells were routinely maintained under standard conditions (37°C and 5% CO 2 in humidified incubator) in a growth medium (GM), consisting of high-glucose Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 10% fetal bovine serum (FBS) and 100 μg/ml penicillin—streptomycin antibiotics; RH30 cells also received 1% L-Glutamine.…”

“…Lack or improper function in some of these protein members have been reported to affect caveolar function, hence disturbing the whole body homeostasis and contributing significantly in the onset and/or progression of diseases like diabetes, muscular dystrophies and cancer [44, 45]. We [46–48] and others [49] have previously documented the expression of Caveolins in RMS and more recently shown the important contribute of Cav-1 and Cavin-1 on tumor growth [48, 50]. In this work we have investigated whether Muscle-Restricted Coiled-coil (MURC)/cavin-4, a plasma membrane and Z-line associated protein exhibiting an overlapping distribution with Cav-3 in heart and muscle tissues [51, 52], may be expressed and play a role in RMS.…”