- Email: [email protected]
Preferential occurrence of RHOA mutation in gastric and colorectal cancers
598
Pathology (2015), 47(6), October
CORRESPONDENCE
6. Gary C, Robertson H, Ruiz B, et al. Retropharyngeal ganglioneuroma presenting with neck stiffness: report of a case and review of the literature. Skull Base 2010; 20: 371–4. 7. Chhabra A, Soldatos T, Durand DJ, et al. The role of magnetic resonance imaging in the diagnostic evaluation of malignant peripheral nerve sheath tumours. Indian J Cancer 2011; 48: 328–34. 8. Evans DG, Baser ME, McGaughran J, et al. Malignant peripheral nerve sheath tumours in neurofibromatosis 1. J Med Genet 2002; 39: 311–4. 9. Chandrasoma P, Shibata D, Radin R, et al. Malignant peripheral nerve sheath tumour arising in an adrenal ganglioneuroma in an adult homosexual. Cancer 1986; 57: 2022–5. 10. Fletcher CD, Fernando IN, Braimbridge MV, et al. Malignant nerve sheath tumour arising in a ganglioneuroma. Histopathology 1988; 12: 445–8. 11. Banks E, Yum M, Brodhecker C, et al. Malignant peripheral nerve sheath tumour in association with paratesticular ganglioneuroma. Cancer 1989; 64: 1738–42. 12. Ghali VS, Gold JE, Vincent RA, et al. Malignant peripheral nerve sheath tumor arising spontaneously from retroperitoneal ganglioneuroma: a case report, review of the literature and immunohistochemical study. Hum Pathol 1992; 23: 72–5. 13. Damiani S, Manetto V, Carrillo G, et al. Malignant peripheral nerve sheath tumour arising in a ‘‘de novo’’ ganglioneuroma. A case report. Tumori 1991; 77: 90–3. 14. Anghileri M, Miceli R, Fiore M, et al. Malignant peripheral nerve sheath tumors: prognostic factors and survival in a series of patients treated at a single institution. Cancer 2006; 107: 1065–74.
DOI: 10.1097/PAT.0000000000000317
Preferential occurrence of RHOA mutation in gastric and colorectal cancers Sir, Ras Homolog Gene Family Member A (RhoA) is a small GTPase protein and is regarded as a prominent regulatory factor in the
Table 1
regulation of cytoskeletal dynamics, transcription, cell cycle progression and cell transformation.1 Overexpression of RhoA is common in many tumours, including prostate, liver and gastric cancers (GC).1,2 A recent whole-exome sequencing study identified somatic mutations of RHOA gene in T cell lymphomas, but not in B cell lymphomas.3 In addition, two other research groups reported frequent RHOA somatic mutations in diffuse- and mixed-type GCs (25.3% and 14.3%).4,5 In colorectal cancers (CRC), RHOA mutation was detected in 1.5% (4/276) of CRCs.6 In GC, RHOA mutations were mainly detected in the N-terminal half and were recurrent at p.R5Q, p.G17V and p.Y42Q.4,5 The RHOA mutants detected in GC caused defective RHOA signalling and increased cell growth and survival.4,5 Together, these data suggest that mutational events in RHOA occur in both haematological and solid tumours, but there might be tumourtype specificity. Also, the recurrent nature of the mutations and their functional consequences suggest that RHOA mutations appear to be oncogenic mutations. One of the main concerns in cancer genetics is whether any mutation found in cancer is specific to few tumour types or is widespread in many tumour types. To see if any other types of human tumours besides T cell lymphomas, GC and CRC harbour RHOA mutations, we analysed various types of human tumours in this study. For this, we analysed the recurrent region (exons 1–2 for amino acids 1–52) of human RHOA gene using genomic DNA from 1567 solid tumours and 628 haematological neoplasms (Table 1) by polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP) assay with four primer pairs. In solid tumours, malignant cells and normal cells were selectively procured from haematoxylin and eosin (H&E) stained slides using a hypodermic needle. Approval was obtained from the College of Medicine’s institutional review board, Catholic University of Korea, for this
RHOA mutations in 2195 tumours RHOA exons 1 and 2
Type of tumours Adulthood AML Adulthood ALL Childhood AML Childhood ALL Multiple myeloma Non-Hodgkin lymphoma Non-small cell lung cancer Gastric carcinoma Diffuse type Mixed type Intestinal type Colorectal carcinoma Breast carcinoma Prostate carcinoma Ovarian epithelial tumour Ovarian stromal tumour Hepatocellular carcinoma Oesophageal squamous cell carcinoma Head/neck carcinoma Renal cell carcinoma Gastrointestinal stromal tumour Leiomyoma Meningioma Sarcoma Total
No. tumours
Wild-type
Mutation
Mutation (%)
198 171 16 175 68 74 213 70 35 15 50 272 94 274 26 97 60 56 35 5 20 68 17 86 2195
197 171 16 174 75 74 211 67 33 14 50 272 94 274 26 97 60 56 35 5 20 68 17 86 2190
1 0 0 1 0 0 0 3 2 1 0 2 0 0 0 0 0 0 0 0 0 0 0 0 5
0.5 0 0 0.6 0 0 0 0 5.7 7.1 0 0.7 0 0 0 0 0 0 0 0 0 0 0 0
ALL, acute lymphoblastic leukemia; AML, acute myelogenous leukemia.
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
CORRESPONDENCE
Table 2
599
Gastric and colorectal cancers with RHOA mutation
Cancer
Sex/age
Histology
MSI status
TNM stage
Nucleotide change (predicted amino acid change)
GC GC GC CRC CRC
M/59 F/51 M/64 M/50 F/69
Mixed Diffuse Diffuse Mucinous Mucinous
MSI-H MSS MSS MSI-H MSI-H
IIIB IIA IIIA IIA IIA
c.14G>A (p.R5Q) c.13C>T (p.R5W) c.125A>C (p.Y42S) c.110C>T (p.T37I) c.77G>A (p.S26N)
CRC, colorectal cancer; F, female; GC, gastric cancer; M, male; MSI-H, high microsatellite instability; MSS, stable microsatellite instability.
study. Radioisotope was incorporated into the PCR products for detection by autoradiogram. Direct DNA sequencing reactions were performed in the cases with mobility shifts in the SSCP. In solid tumours, PCR-SSCP analysis of RHOA gene led to identification of aberrant bands in five cases (3 GCs and 2 CRCs) (Tables 1 and 2). DNA sequencing analysis identified that all of the aberrant bands represented somatic mutations. In the GCs, the mutations were identified in both diffuse- and mixed-type GCs, but not in intestinal type. Of note, in CRC, all of the two mutations were identified in those with high microsatellite instability (MSI-H). None of the SSCP from the other solid tumours and haematological tumours revealed aberrantly migrating bands compared to wild-type bands from the normal tissues, indicating there was no evidence of RHOA mutation. Previous reports on the high incidence of RHOA mutations in a solid tumour (GC) as well as in haematological tumours (T cell neoplasia) led us to further analyse the mutations in other tumours that had not been studied for the mutations. We confirmed the previous data that GC harboured the recurrent RHOA mutations. In addition, we found that CRC, albeit less frequently, harboured RHOA mutations. However, our data showed that RHOA mutations were absent in many other tumours analysed (Table 1). Together with the previous reports,4,5 our results indicate that oncogenic RHOA mutation is present in GC and CRC, but not in other solid tumours, suggesting its role in the development of gastrointestinal cancers. Our data may provide useful information on possible clinical applications targeting RHOA in cancer patients. Acknowledgements: This study was supported by a grant from Korea Research Foundation (2012R1A5A20047939). Conflicts of interest and sources of funding: The authors state that there are no conflicts of interest to disclose. Min Sung Kim Nam Jin Yoo Sug Hyung Lee Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea Contact Dr Sug Hyung Lee. E-mail: [email protected] 1. Karlsson R, Pedersen ED, Wang Z, Brakebusch C. Rho GTPase function in tumorigenesis. Biochim Biophys Acta 1796; 2009: 91–8. 2. Li XR, Ji F, Ouyang J, Wu W, Qian LY, Yang KY. Overexpression of RhoA is associated with poor prognosis in hepatocellular carcinoma. Eur J Surg Oncol 2006; 32: 1130–4.
3. Yoo HY, Sung MK, Lee SH, et al. A recurrent inactivating mutation in RHOA GTPase in angioimmunoblastic T cell lymphoma. Nat Genet 2014; 46: 371–5. 4. Wang K, Yuen ST, Xu J, et al. Whole-genome sequencing and comprehensive molecular profiling identify new driver mutations in gastric cancer. Nat Genet 2014; 46: 573–82. 5. Kakiuchi M, Nishizawa T, Ueda H, et al. Recurrent gain-of-function mutations of RHOA in diffuse-type gastric carcinoma. Nat Genet 2014; 46: 583–7. 6. Cancer Genome Atlas Network. Comprehensive molecular characterization of human colon and rectal cancer. Nature 2012; 487: 330–7.
DOI: 10.1097/PAT.0000000000000305
Spiral bodies in pulse granulomas are remnant plant vascular structures Sir, Pulse granulomas (PG), or hyaline ring granulomas, are unique lesions composed of variably sized rings (100–400 mm) of pale eosinophilic amorphous material surrounded by or encasing multinucleated giant cells and chronic inflammation. They were originally described in association with oral pathologies where they were felt to represent either a foreign body type reaction to plant material or a degenerative vascular change resulting from a localised vasculitis; however, most evidence now supports that they are a reaction to plant material.1 PG have been described in a variety of locations that may have potential communication with the luminal gastrointestinal tract, presumably resulting from spillage of partially digested plant material out of the GI tract to produce the PG. One report of colonic peridiverticular PG showed a small, unidentified ‘spiral body’ within the PG that had not previously been described in the literature and was of uncertain origin.2 We recently identified a case with numerous oral PG and a foreign body type multinucleated giant cell reaction surrounding morphologically similar ‘spiral bodies’. These spiral bodies were larger and better preserved than in the previous report, which allowed us to identify the precise origin of these spiral bodies as remnant plant vascular structures (helical xylem elements). The spiral bodies were discovered in sections from a partial mandibulectomy for biopsy proven ameloblastoma. Dense reactive fibrous tissue was noted adjacent to the previously biopsied lesion with patchy chronic inflammation and foreign body giant cell reaction surrounding scattered deposits of easily recognisable and partially digested plant material. PG were also abundant with pale eosinophilic hyaline rings ranging up to 300 mm in diameter associated with multinucleated giant cells, lymphocytes, and plasma cells. Staining with Congo red
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
Pathology (2015), 47(6), October
CORRESPONDENCE
6. Gary C, Robertson H, Ruiz B, et al. Retropharyngeal ganglioneuroma presenting with neck stiffness: report of a case and review of the literature. Skull Base 2010; 20: 371–4. 7. Chhabra A, Soldatos T, Durand DJ, et al. The role of magnetic resonance imaging in the diagnostic evaluation of malignant peripheral nerve sheath tumours. Indian J Cancer 2011; 48: 328–34. 8. Evans DG, Baser ME, McGaughran J, et al. Malignant peripheral nerve sheath tumours in neurofibromatosis 1. J Med Genet 2002; 39: 311–4. 9. Chandrasoma P, Shibata D, Radin R, et al. Malignant peripheral nerve sheath tumour arising in an adrenal ganglioneuroma in an adult homosexual. Cancer 1986; 57: 2022–5. 10. Fletcher CD, Fernando IN, Braimbridge MV, et al. Malignant nerve sheath tumour arising in a ganglioneuroma. Histopathology 1988; 12: 445–8. 11. Banks E, Yum M, Brodhecker C, et al. Malignant peripheral nerve sheath tumour in association with paratesticular ganglioneuroma. Cancer 1989; 64: 1738–42. 12. Ghali VS, Gold JE, Vincent RA, et al. Malignant peripheral nerve sheath tumor arising spontaneously from retroperitoneal ganglioneuroma: a case report, review of the literature and immunohistochemical study. Hum Pathol 1992; 23: 72–5. 13. Damiani S, Manetto V, Carrillo G, et al. Malignant peripheral nerve sheath tumour arising in a ‘‘de novo’’ ganglioneuroma. A case report. Tumori 1991; 77: 90–3. 14. Anghileri M, Miceli R, Fiore M, et al. Malignant peripheral nerve sheath tumors: prognostic factors and survival in a series of patients treated at a single institution. Cancer 2006; 107: 1065–74.
DOI: 10.1097/PAT.0000000000000317
Preferential occurrence of RHOA mutation in gastric and colorectal cancers Sir, Ras Homolog Gene Family Member A (RhoA) is a small GTPase protein and is regarded as a prominent regulatory factor in the
Table 1
regulation of cytoskeletal dynamics, transcription, cell cycle progression and cell transformation.1 Overexpression of RhoA is common in many tumours, including prostate, liver and gastric cancers (GC).1,2 A recent whole-exome sequencing study identified somatic mutations of RHOA gene in T cell lymphomas, but not in B cell lymphomas.3 In addition, two other research groups reported frequent RHOA somatic mutations in diffuse- and mixed-type GCs (25.3% and 14.3%).4,5 In colorectal cancers (CRC), RHOA mutation was detected in 1.5% (4/276) of CRCs.6 In GC, RHOA mutations were mainly detected in the N-terminal half and were recurrent at p.R5Q, p.G17V and p.Y42Q.4,5 The RHOA mutants detected in GC caused defective RHOA signalling and increased cell growth and survival.4,5 Together, these data suggest that mutational events in RHOA occur in both haematological and solid tumours, but there might be tumourtype specificity. Also, the recurrent nature of the mutations and their functional consequences suggest that RHOA mutations appear to be oncogenic mutations. One of the main concerns in cancer genetics is whether any mutation found in cancer is specific to few tumour types or is widespread in many tumour types. To see if any other types of human tumours besides T cell lymphomas, GC and CRC harbour RHOA mutations, we analysed various types of human tumours in this study. For this, we analysed the recurrent region (exons 1–2 for amino acids 1–52) of human RHOA gene using genomic DNA from 1567 solid tumours and 628 haematological neoplasms (Table 1) by polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP) assay with four primer pairs. In solid tumours, malignant cells and normal cells were selectively procured from haematoxylin and eosin (H&E) stained slides using a hypodermic needle. Approval was obtained from the College of Medicine’s institutional review board, Catholic University of Korea, for this
RHOA mutations in 2195 tumours RHOA exons 1 and 2
Type of tumours Adulthood AML Adulthood ALL Childhood AML Childhood ALL Multiple myeloma Non-Hodgkin lymphoma Non-small cell lung cancer Gastric carcinoma Diffuse type Mixed type Intestinal type Colorectal carcinoma Breast carcinoma Prostate carcinoma Ovarian epithelial tumour Ovarian stromal tumour Hepatocellular carcinoma Oesophageal squamous cell carcinoma Head/neck carcinoma Renal cell carcinoma Gastrointestinal stromal tumour Leiomyoma Meningioma Sarcoma Total
No. tumours
Wild-type
Mutation
Mutation (%)
198 171 16 175 68 74 213 70 35 15 50 272 94 274 26 97 60 56 35 5 20 68 17 86 2195
197 171 16 174 75 74 211 67 33 14 50 272 94 274 26 97 60 56 35 5 20 68 17 86 2190
1 0 0 1 0 0 0 3 2 1 0 2 0 0 0 0 0 0 0 0 0 0 0 0 5
0.5 0 0 0.6 0 0 0 0 5.7 7.1 0 0.7 0 0 0 0 0 0 0 0 0 0 0 0
ALL, acute lymphoblastic leukemia; AML, acute myelogenous leukemia.
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
CORRESPONDENCE
Table 2
599
Gastric and colorectal cancers with RHOA mutation
Cancer
Sex/age
Histology
MSI status
TNM stage
Nucleotide change (predicted amino acid change)
GC GC GC CRC CRC
M/59 F/51 M/64 M/50 F/69
Mixed Diffuse Diffuse Mucinous Mucinous
MSI-H MSS MSS MSI-H MSI-H
IIIB IIA IIIA IIA IIA
c.14G>A (p.R5Q) c.13C>T (p.R5W) c.125A>C (p.Y42S) c.110C>T (p.T37I) c.77G>A (p.S26N)
CRC, colorectal cancer; F, female; GC, gastric cancer; M, male; MSI-H, high microsatellite instability; MSS, stable microsatellite instability.
study. Radioisotope was incorporated into the PCR products for detection by autoradiogram. Direct DNA sequencing reactions were performed in the cases with mobility shifts in the SSCP. In solid tumours, PCR-SSCP analysis of RHOA gene led to identification of aberrant bands in five cases (3 GCs and 2 CRCs) (Tables 1 and 2). DNA sequencing analysis identified that all of the aberrant bands represented somatic mutations. In the GCs, the mutations were identified in both diffuse- and mixed-type GCs, but not in intestinal type. Of note, in CRC, all of the two mutations were identified in those with high microsatellite instability (MSI-H). None of the SSCP from the other solid tumours and haematological tumours revealed aberrantly migrating bands compared to wild-type bands from the normal tissues, indicating there was no evidence of RHOA mutation. Previous reports on the high incidence of RHOA mutations in a solid tumour (GC) as well as in haematological tumours (T cell neoplasia) led us to further analyse the mutations in other tumours that had not been studied for the mutations. We confirmed the previous data that GC harboured the recurrent RHOA mutations. In addition, we found that CRC, albeit less frequently, harboured RHOA mutations. However, our data showed that RHOA mutations were absent in many other tumours analysed (Table 1). Together with the previous reports,4,5 our results indicate that oncogenic RHOA mutation is present in GC and CRC, but not in other solid tumours, suggesting its role in the development of gastrointestinal cancers. Our data may provide useful information on possible clinical applications targeting RHOA in cancer patients. Acknowledgements: This study was supported by a grant from Korea Research Foundation (2012R1A5A20047939). Conflicts of interest and sources of funding: The authors state that there are no conflicts of interest to disclose. Min Sung Kim Nam Jin Yoo Sug Hyung Lee Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea Contact Dr Sug Hyung Lee. E-mail: [email protected] 1. Karlsson R, Pedersen ED, Wang Z, Brakebusch C. Rho GTPase function in tumorigenesis. Biochim Biophys Acta 1796; 2009: 91–8. 2. Li XR, Ji F, Ouyang J, Wu W, Qian LY, Yang KY. Overexpression of RhoA is associated with poor prognosis in hepatocellular carcinoma. Eur J Surg Oncol 2006; 32: 1130–4.
3. Yoo HY, Sung MK, Lee SH, et al. A recurrent inactivating mutation in RHOA GTPase in angioimmunoblastic T cell lymphoma. Nat Genet 2014; 46: 371–5. 4. Wang K, Yuen ST, Xu J, et al. Whole-genome sequencing and comprehensive molecular profiling identify new driver mutations in gastric cancer. Nat Genet 2014; 46: 573–82. 5. Kakiuchi M, Nishizawa T, Ueda H, et al. Recurrent gain-of-function mutations of RHOA in diffuse-type gastric carcinoma. Nat Genet 2014; 46: 583–7. 6. Cancer Genome Atlas Network. Comprehensive molecular characterization of human colon and rectal cancer. Nature 2012; 487: 330–7.
DOI: 10.1097/PAT.0000000000000305
Spiral bodies in pulse granulomas are remnant plant vascular structures Sir, Pulse granulomas (PG), or hyaline ring granulomas, are unique lesions composed of variably sized rings (100–400 mm) of pale eosinophilic amorphous material surrounded by or encasing multinucleated giant cells and chronic inflammation. They were originally described in association with oral pathologies where they were felt to represent either a foreign body type reaction to plant material or a degenerative vascular change resulting from a localised vasculitis; however, most evidence now supports that they are a reaction to plant material.1 PG have been described in a variety of locations that may have potential communication with the luminal gastrointestinal tract, presumably resulting from spillage of partially digested plant material out of the GI tract to produce the PG. One report of colonic peridiverticular PG showed a small, unidentified ‘spiral body’ within the PG that had not previously been described in the literature and was of uncertain origin.2 We recently identified a case with numerous oral PG and a foreign body type multinucleated giant cell reaction surrounding morphologically similar ‘spiral bodies’. These spiral bodies were larger and better preserved than in the previous report, which allowed us to identify the precise origin of these spiral bodies as remnant plant vascular structures (helical xylem elements). The spiral bodies were discovered in sections from a partial mandibulectomy for biopsy proven ameloblastoma. Dense reactive fibrous tissue was noted adjacent to the previously biopsied lesion with patchy chronic inflammation and foreign body giant cell reaction surrounding scattered deposits of easily recognisable and partially digested plant material. PG were also abundant with pale eosinophilic hyaline rings ranging up to 300 mm in diameter associated with multinucleated giant cells, lymphocytes, and plasma cells. Staining with Congo red
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.