Journal reading 報告者： PGY2 曾智皇報告日期 : 103.06.10 指導老師 : 林立民醫師陳玉昆醫師

Journal reading

報告者： PGY2 曾智皇報告日期 : 103.06.10指導老師 : 林立民醫師陳玉昆醫師

1. Introduction2. CA-IX expression and prognosis in OSCC3. CA-IX expression in other HNSCCs4. Relationship between CA-IX and

chemoresistance or radioresistance5. The relationship between CA-IX and other

molecules6. Role of CA-IX as therapeutic target against

cancer7. Conclusions





Introduction• Hypoxia and tumor cell proliferation

determine response to surgery, CT, and RT

• Tumor hypoxia a. The promotion of genetic instability b. The invasive capacity of tumor cellsc. Metastasisd. Worsening of the clinical evolution loss of the apoptotic capacity of cells

• Among the hypoxia markers, we will focus on the exogenous hypoxia markers, mainly 2-nitroimidazole, pimonidazole, and EF-5

• In addition to exogenous markers, there are endogenous hypoxia markers, controlled by hypoxia-related genes, formed by HIF-1

• HIF-1 a. Related to the von Hippel-Lindau (vHL) tumor

suppressor protein during oncogenesis b. Controls several target genes that involve the

energy metabolism, angiogenesis (VEGF) and transmembrane carbonic anhydrases (CAs)

• CAs are transmembrane Zn metalo-enzymes catalyze reversible hydration of carbon

dioxide in carbonic acid involved in respiration and acid-base

equilibrium

• CA-IX and CA-XII are the two tumor-related carbonic anhydrases

• CA-IX is largely expressed in tumor cell lines and shows moderate-low expression in a healthy gastrointestinal tract

• CA-IX expression has been thoroughly described in different tumors

however, this has not been so for head and neck carcinomas









• Hoogsteen et al 2005 a. Analyzed CA-IX expression and IdUrd in a

series of 60 HNSCC cases, including 3 OSCC cases

b. Joint expression of CA-IX and IdUrd responsible for repopulation and disease progression

• Le et al 2007a. Elevated correlation of hypoxia levels and CA-

IXb. CA-IX not related to any of the prognostic

variables

• Kaanders et al 2002a. Studied distribution of pimonidazole and CA-

IX

b. Patients with hypoxic tumors and low vascular density showed worse locoregional control

Although no relation was found between CA-IX expression and treatment outcome

• HNSCCs a. Hypoxic tumors by definitionb. Frequently diagnosed in very advanced

stagesc. In HPV-positive cases that normally have

better prognosis

• Brockton et al 2011 Showed that a high stromal expression of CA-

IX is related to a reduced average survival in p16-negative tumors

• Kong et al 2009a. 44% (36 of 82) HNSCC cases under study

presented a strong HPV pyrosequencing signal

b. No relation with tumor hypoxia and CA-IX expression





• Koukourakis et al 2001

a. CA-IX expression (26.6%, 20 of 75) takes place mainly in tumors with low vascularization (CD-31), necrosis areas

b. CA-IX expression related to a poor overall response

These results were confirmed by Jonathan et al and Beasley et al

• Bhattacharya et al 2004a. HNSCC xenograft

b. Lack of microvessels in well-differentiated areas of the xenograft related to hypoxia and positive for CA-IX

a limited use of chemotherapeutic drugs resistance to Irinotecan therapy

c. Hypoxia promoted the creation of resistant cell subpopulations

• Chintala et al 2010a. The effect of Se-methylselenocysteine in

HNSCC cell lines and xenografts

b. In cells and hypoxic areas, the combination of both drugs

1. reduced HIF-1a levels 2. lowered CA-IX levels

• Zheng et al 2010a. Transformed an OSCC into PYM resistant

and crossresistant to paclitaxel, Adriamycin, mitomycin

b. Application of CA inhibitor, acetazolamide, and CA-IX silencing with oligonucleotides

PH ↑ in resistant cells increase of chemosensitivity to PYM

Eriksen et al 2007a. CA-IX as prognostic marker in a series of 320

HNSCCs undergoing radiotherapy + nimorazole

b. CA-IX is not related to any clinical and pathological, prognostic parameters

• Patients treated with ARCON vs. conventional surgery ± radiotherapy

the hypoxia and vascula density levels have no influence on treatment response

• Jonathan et al 2006 Relationship between CA-IX and the lack of

locoregional controldisappears when tumors are treated with

ARCON

*accelerated radiotherapy combined with carbogen and nicotinamide

Koukourakis et al 2006Joint expression of HIF-2a and CA-IX is

responsible for poor CHART results

* Continuous hyperfractionated accelerated radiotherapy





HIF• HIF-1a transcription is the regulating factor in

cellular response to hypoxia

• In the case of OSCC, HIF-1a prevents apoptosis of tumor cells

• Zhu et al 2010 OSCC cell lines are cultivated with 1% O2 expression of mRNA CA-IX is regulated by HIF-1a

• Chintala et al 2010 Application of Se-methylselenocysteine

combined with irinotecan HIF-1a ↓ CA-IX ↓

• Koukourakis et ala. CA-IX expression worse survival ratesb. HIF-2a worse locoregional controlc. Joint expression provoked an additive effect

confirm relation between both markers

• Eckert et al 2010 HIF-1a & CA-IX

a. low expression of both proteins survived an average of 54.8 months

b. high HIF-1a and low CA-IX expression survived an average of 37.6 months;

tumor-related death risk was 4.97-fold

• Roh et al 2009 Statistically significant relationship between

CA-IX and HIF-1a and HIF-2a

• Winter et al Not confirm a positive correlation with HIF-1a

nor HIF-2a

Ki-67• Kim et al 2007 CA-IX & Ki-67

a. Correlation between bothb. Established three patterns: (1) high risk (elevated CA-IX ⁄ Ki-67)

(2) low risk (low CA-IX ⁄ Ki- 67)

(3) moderate risk (one of the two is elevated)

The high-risk group was an independent prognostic factor for average survival and disease-free survival

• Kondo et al 2011 no relationship between Ki-67 expression and

CA-IX

GLUT-1• Schutter et al 2005 CA-IX & GLUT-1 (glucose transporter-1)

a. CA-IX expression was not related to 1. any of the clinical, pathological, or prognostic parameters 2. the expression of GLUT-1

• Kondo et al 2011 & Jonathan et al 2006 not found relation between GLUT-1

expression and CA-IX

Erythropoietin (Epo) and erythropoietin receptor (EpoR)

• Winter et al 2005a. Tried to link tumor hypoxia and its main

marker, CA-IX, with Hb, Epo, and EpoRb. Positive correlation in CA-IX and Epo, but not

EpoRc. No correlation between Hb and Epo or EpoR

Other molecules

• Le et al 2007 significant relationship between intense CA-IX

expression and hypoxia-related proteins: BNIP3L, LOX, CTGF, Ephrin A1, GAL-1

• Le et al 2007 Positive correlation between the expression of

CA-IX and Galectin-1 and their relation with treatment outcome

• Silva et al 2010 Co-expression of CA-IX and MVP (major vault

protein) confers tumors a significantly lesser chance of locoregional control

• Gee et al 2010a. Abnormally high levels of microRNA hsa-miR-

210 in 46 HNSCC patients b. Statistically significant relationship between

hypoxia markers such as HIF-1a, the TWIST1 gene, and CA-IX

c. Locoregional recurrence with a smaller average survival

• Schutter et al 2006a. Analyzing the relation between micro-

satellite alterations and HNSCC tumor hypoxia

b. LOH (loss of heterozygosity) is very frequent in regions close to p53, specifically in D17S799, in patients that simultaneously showed high CA-IX expression

supporting the theory of the relationship between p53 and hypoxia





• CA-IX and XII are predominantly found in tumor cells

• Hydrating carbon dioxide to protons and bicarbonate, these CAs contribute significantly to the extracellular acidification of solid tumors

• CA-IX is overexpressed in many tumors in response to the HIF pathway

• Design campaigns of inhibitors against this novel, recently validated antitumor target

• Obtaining compounds that specifically target the tumor-associated isoforms CA-IX and XII

• Coumarin and thiocoumarins are the most important such new CAIs

Lou Y et al 2011Pacchiano F et al 2011 • The most interesting CAIs reported to date are

the ureido-sulfonamide and the glycosyl coumarin (low nanomolar CA-IX selective inhibitors)

which strongly inhibit the growth of both

primary tumors and metastases in several animal models of breast cancer

• Similar animal model of breast cancer cell lines which does not express CA-IX has been used as negative control

no effects on the growth of the tumors have been evidenced after treatment with sulfonamide ⁄ coumarin CAIs

demonstrated the potential of CA-IX inhibition for designing antitumor ⁄ antimetastatic agents possessing a novel mechanism of action

Zatovicova M et al 2010 • M75 is a highly specific anti-CA-IX mAb

targeting the PG domain of CA-IX used in immunohistochemical and western

blot studies for evidencing CA-IX

Siebels M et al 2011 • WX-G250 (Girentuximab) is another anti-CA-IX

chimeric monoclonal antibody in phase III clinical trials as adjuvant therapy for the treatment of non-metastasized RCC

• Tumor-associated CAs are indeed almost ideal targets for designing novel and innovative anticancer drugs

• Interfere with tumor acidification by a mechanism of action not yet exploited by the classical cytostatic drugs





• Hypoxia in solid tumors is a decisive factor for the outcome of HNSCCs

• Hypoxia in solid tumors with chemoresistance and the failure of radiotherapy, both conventional and concomitant, in which CA-IX seems to play an important role

• Several mAbs (girentuximab, and its 124I-radiolabelled variant) targeting CA-IX

in advanced clinical trials both for a. treatment b. imaging of hypoxic tumors overexpressing this enzyme

• Two small molecule CA-IX inhibitors 1. sulfonamide 2. glycosyl coumarin both for imaging and treatment of solid

tumors and metastases in which CA-IX is present

• Further studies of these tumors are needed to confirm

a. the use of CA-IX as a prognostic marker b. evaluate its possible inhibition with minimal adverse effects c. reducing the risk of metastasis d. favoring the action of chemotherapeutic drugs and radiotherapy

Thank you for your attention

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Journal reading 報告者： PGY2 曾智皇 報告日期 : 103.06.10 指導老師 : 林立民 醫師 陳玉昆 醫師

Journal reading 報告者： PGY2 曾智皇報告日期 : 103.06.10 指導老師 : 林立民醫師陳玉昆醫師