MSP430 LCD Interfacing via I2C

I am new at this. I am trying to interfacing 1602A LCD display with MSP430G2553 via PCF8574. When I run the code, nothing happens:

#include <msp430.h>

unsigned int *ptxData;
unsigned int count = 0;
// [0..3] -> power on, [4..5] -> function set, [6..7] -> display off, cursor off, blink off
// [8..9] -> clear screen, [10..11] -> right, do not shift, [12..13] -> display on, cursor on
// [14..15] -> write char 'B'
unsigned int txData[] = {0x03, 0x03, 0x03, 0x02, 0x02, 0x00, 0x00, 0x08, 0x00, 0x01, 0x00, 0x06, 0x00, 0x0F, 0x24, 0x22};

void main() {
    WDTCTL = WDTPW | WDTHOLD;

    // for i2c pins
    P1SEL = 0xC0;
    P1SEL2 = 0xC0;

    // i2c config
    UCB0CTL1 |= UCSWRST;
    UCB0CTL0 = UCMST | UCMODE_3 | UCSYNC;
    UCB0CTL1 = UCSSEL_3;
    UCB0BR0 = 12;
    UCB0BR1 = 0;
    UCB0I2CSA = 0x27;   // slave address
    UCB0CTL1 &= ~UCSWRST;

    // enable tx interrupt
    IE2 |= UCB0TXIE;
    _enable_interrupts();

    // start to transmit data
    ptxData = txData;
    UCB0CTL1 |= UCTR + UCTXSTT;

    while (1);
}

#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void){
    // send txData elements one by one
    UCB0TXBUF = *ptxData;
    count++;
    *ptxData++;

    // if txData ends, start from beginning
    if (count == 16) {
        count = 0;
        ptxData -= 16;
    }
}

What am I missing, can you help me?